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- <ul>
- <li><a class="reference internal" href="#"><code class="xref py py-mod docutils literal notranslate"><span class="pre">json</span></code> — JSON encoder and decoder</a><ul>
- <li><a class="reference internal" href="#basic-usage">Basic Usage</a></li>
- <li><a class="reference internal" href="#encoders-and-decoders">Encoders and Decoders</a></li>
- <li><a class="reference internal" href="#exceptions">Exceptions</a></li>
- <li><a class="reference internal" href="#standard-compliance-and-interoperability">Standard Compliance and Interoperability</a><ul>
- <li><a class="reference internal" href="#character-encodings">Character Encodings</a></li>
- <li><a class="reference internal" href="#infinite-and-nan-number-values">Infinite and NaN Number Values</a></li>
- <li><a class="reference internal" href="#repeated-names-within-an-object">Repeated Names Within an Object</a></li>
- <li><a class="reference internal" href="#top-level-non-object-non-array-values">Top-level Non-Object, Non-Array Values</a></li>
- <li><a class="reference internal" href="#implementation-limitations">Implementation Limitations</a></li>
- </ul>
- </li>
- <li><a class="reference internal" href="#module-json.tool">Command Line Interface</a><ul>
- <li><a class="reference internal" href="#command-line-options">Command line options</a></li>
- </ul>
- </li>
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- <section id="module-json">
- <span id="json-json-encoder-and-decoder"></span><h1><a class="reference internal" href="#module-json" title="json: Encode and decode the JSON format."><code class="xref py py-mod docutils literal notranslate"><span class="pre">json</span></code></a> — JSON encoder and decoder<a class="headerlink" href="#module-json" title="Link to this heading">¶</a></h1>
- <p><strong>Source code:</strong> <a class="reference external" href="https://github.com/python/cpython/tree/3.12/Lib/json/__init__.py">Lib/json/__init__.py</a></p>
- <hr class="docutils" />
- <p><a class="reference external" href="https://json.org">JSON (JavaScript Object Notation)</a>, specified by
- <span class="target" id="index-0"></span><a class="rfc reference external" href="https://datatracker.ietf.org/doc/html/rfc7159.html"><strong>RFC 7159</strong></a> (which obsoletes <span class="target" id="index-1"></span><a class="rfc reference external" href="https://datatracker.ietf.org/doc/html/rfc4627.html"><strong>RFC 4627</strong></a>) and by
- <a class="reference external" href="https://www.ecma-international.org/publications-and-standards/standards/ecma-404/">ECMA-404</a>,
- is a lightweight data interchange format inspired by
- <a class="reference external" href="https://en.wikipedia.org/wiki/JavaScript">JavaScript</a> object literal syntax
- (although it is not a strict subset of JavaScript <a class="footnote-reference brackets" href="#rfc-errata" id="id1" role="doc-noteref"><span class="fn-bracket">[</span>1<span class="fn-bracket">]</span></a> ).</p>
- <div class="admonition warning">
- <p class="admonition-title">Warning</p>
- <p>Be cautious when parsing JSON data from untrusted sources. A malicious
- JSON string may cause the decoder to consume considerable CPU and memory
- resources. Limiting the size of data to be parsed is recommended.</p>
- </div>
- <p><a class="reference internal" href="#module-json" title="json: Encode and decode the JSON format."><code class="xref py py-mod docutils literal notranslate"><span class="pre">json</span></code></a> exposes an API familiar to users of the standard library
- <a class="reference internal" href="marshal.html#module-marshal" title="marshal: Convert Python objects to streams of bytes and back (with different constraints)."><code class="xref py py-mod docutils literal notranslate"><span class="pre">marshal</span></code></a> and <a class="reference internal" href="pickle.html#module-pickle" title="pickle: Convert Python objects to streams of bytes and back."><code class="xref py py-mod docutils literal notranslate"><span class="pre">pickle</span></code></a> modules.</p>
- <p>Encoding basic Python object hierarchies:</p>
- <div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="kn">import</span> <span class="nn">json</span>
- <span class="gp">>>> </span><span class="n">json</span><span class="o">.</span><span class="n">dumps</span><span class="p">([</span><span class="s1">'foo'</span><span class="p">,</span> <span class="p">{</span><span class="s1">'bar'</span><span class="p">:</span> <span class="p">(</span><span class="s1">'baz'</span><span class="p">,</span> <span class="kc">None</span><span class="p">,</span> <span class="mf">1.0</span><span class="p">,</span> <span class="mi">2</span><span class="p">)}])</span>
- <span class="go">'["foo", {"bar": ["baz", null, 1.0, 2]}]'</span>
- <span class="gp">>>> </span><span class="nb">print</span><span class="p">(</span><span class="n">json</span><span class="o">.</span><span class="n">dumps</span><span class="p">(</span><span class="s2">"</span><span class="se">\"</span><span class="s2">foo</span><span class="se">\b</span><span class="s2">ar"</span><span class="p">))</span>
- <span class="go">"\"foo\bar"</span>
- <span class="gp">>>> </span><span class="nb">print</span><span class="p">(</span><span class="n">json</span><span class="o">.</span><span class="n">dumps</span><span class="p">(</span><span class="s1">'</span><span class="se">\u1234</span><span class="s1">'</span><span class="p">))</span>
- <span class="go">"\u1234"</span>
- <span class="gp">>>> </span><span class="nb">print</span><span class="p">(</span><span class="n">json</span><span class="o">.</span><span class="n">dumps</span><span class="p">(</span><span class="s1">'</span><span class="se">\\</span><span class="s1">'</span><span class="p">))</span>
- <span class="go">"\\"</span>
- <span class="gp">>>> </span><span class="nb">print</span><span class="p">(</span><span class="n">json</span><span class="o">.</span><span class="n">dumps</span><span class="p">({</span><span class="s2">"c"</span><span class="p">:</span> <span class="mi">0</span><span class="p">,</span> <span class="s2">"b"</span><span class="p">:</span> <span class="mi">0</span><span class="p">,</span> <span class="s2">"a"</span><span class="p">:</span> <span class="mi">0</span><span class="p">},</span> <span class="n">sort_keys</span><span class="o">=</span><span class="kc">True</span><span class="p">))</span>
- <span class="go">{"a": 0, "b": 0, "c": 0}</span>
- <span class="gp">>>> </span><span class="kn">from</span> <span class="nn">io</span> <span class="kn">import</span> <span class="n">StringIO</span>
- <span class="gp">>>> </span><span class="n">io</span> <span class="o">=</span> <span class="n">StringIO</span><span class="p">()</span>
- <span class="gp">>>> </span><span class="n">json</span><span class="o">.</span><span class="n">dump</span><span class="p">([</span><span class="s1">'streaming API'</span><span class="p">],</span> <span class="n">io</span><span class="p">)</span>
- <span class="gp">>>> </span><span class="n">io</span><span class="o">.</span><span class="n">getvalue</span><span class="p">()</span>
- <span class="go">'["streaming API"]'</span>
- </pre></div>
- </div>
- <p>Compact encoding:</p>
- <div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="kn">import</span> <span class="nn">json</span>
- <span class="gp">>>> </span><span class="n">json</span><span class="o">.</span><span class="n">dumps</span><span class="p">([</span><span class="mi">1</span><span class="p">,</span> <span class="mi">2</span><span class="p">,</span> <span class="mi">3</span><span class="p">,</span> <span class="p">{</span><span class="s1">'4'</span><span class="p">:</span> <span class="mi">5</span><span class="p">,</span> <span class="s1">'6'</span><span class="p">:</span> <span class="mi">7</span><span class="p">}],</span> <span class="n">separators</span><span class="o">=</span><span class="p">(</span><span class="s1">','</span><span class="p">,</span> <span class="s1">':'</span><span class="p">))</span>
- <span class="go">'[1,2,3,{"4":5,"6":7}]'</span>
- </pre></div>
- </div>
- <p>Pretty printing:</p>
- <div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="kn">import</span> <span class="nn">json</span>
- <span class="gp">>>> </span><span class="nb">print</span><span class="p">(</span><span class="n">json</span><span class="o">.</span><span class="n">dumps</span><span class="p">({</span><span class="s1">'4'</span><span class="p">:</span> <span class="mi">5</span><span class="p">,</span> <span class="s1">'6'</span><span class="p">:</span> <span class="mi">7</span><span class="p">},</span> <span class="n">sort_keys</span><span class="o">=</span><span class="kc">True</span><span class="p">,</span> <span class="n">indent</span><span class="o">=</span><span class="mi">4</span><span class="p">))</span>
- <span class="go">{</span>
- <span class="go"> "4": 5,</span>
- <span class="go"> "6": 7</span>
- <span class="go">}</span>
- </pre></div>
- </div>
- <p>Decoding JSON:</p>
- <div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="kn">import</span> <span class="nn">json</span>
- <span class="gp">>>> </span><span class="n">json</span><span class="o">.</span><span class="n">loads</span><span class="p">(</span><span class="s1">'["foo", {"bar":["baz", null, 1.0, 2]}]'</span><span class="p">)</span>
- <span class="go">['foo', {'bar': ['baz', None, 1.0, 2]}]</span>
- <span class="gp">>>> </span><span class="n">json</span><span class="o">.</span><span class="n">loads</span><span class="p">(</span><span class="s1">'"</span><span class="se">\\</span><span class="s1">"foo</span><span class="se">\\</span><span class="s1">bar"'</span><span class="p">)</span>
- <span class="go">'"foo\x08ar'</span>
- <span class="gp">>>> </span><span class="kn">from</span> <span class="nn">io</span> <span class="kn">import</span> <span class="n">StringIO</span>
- <span class="gp">>>> </span><span class="n">io</span> <span class="o">=</span> <span class="n">StringIO</span><span class="p">(</span><span class="s1">'["streaming API"]'</span><span class="p">)</span>
- <span class="gp">>>> </span><span class="n">json</span><span class="o">.</span><span class="n">load</span><span class="p">(</span><span class="n">io</span><span class="p">)</span>
- <span class="go">['streaming API']</span>
- </pre></div>
- </div>
- <p>Specializing JSON object decoding:</p>
- <div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="kn">import</span> <span class="nn">json</span>
- <span class="gp">>>> </span><span class="k">def</span> <span class="nf">as_complex</span><span class="p">(</span><span class="n">dct</span><span class="p">):</span>
- <span class="gp">... </span> <span class="k">if</span> <span class="s1">'__complex__'</span> <span class="ow">in</span> <span class="n">dct</span><span class="p">:</span>
- <span class="gp">... </span> <span class="k">return</span> <span class="nb">complex</span><span class="p">(</span><span class="n">dct</span><span class="p">[</span><span class="s1">'real'</span><span class="p">],</span> <span class="n">dct</span><span class="p">[</span><span class="s1">'imag'</span><span class="p">])</span>
- <span class="gp">... </span> <span class="k">return</span> <span class="n">dct</span>
- <span class="gp">...</span>
- <span class="gp">>>> </span><span class="n">json</span><span class="o">.</span><span class="n">loads</span><span class="p">(</span><span class="s1">'{"__complex__": true, "real": 1, "imag": 2}'</span><span class="p">,</span>
- <span class="gp">... </span> <span class="n">object_hook</span><span class="o">=</span><span class="n">as_complex</span><span class="p">)</span>
- <span class="go">(1+2j)</span>
- <span class="gp">>>> </span><span class="kn">import</span> <span class="nn">decimal</span>
- <span class="gp">>>> </span><span class="n">json</span><span class="o">.</span><span class="n">loads</span><span class="p">(</span><span class="s1">'1.1'</span><span class="p">,</span> <span class="n">parse_float</span><span class="o">=</span><span class="n">decimal</span><span class="o">.</span><span class="n">Decimal</span><span class="p">)</span>
- <span class="go">Decimal('1.1')</span>
- </pre></div>
- </div>
- <p>Extending <a class="reference internal" href="#json.JSONEncoder" title="json.JSONEncoder"><code class="xref py py-class docutils literal notranslate"><span class="pre">JSONEncoder</span></code></a>:</p>
- <div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="kn">import</span> <span class="nn">json</span>
- <span class="gp">>>> </span><span class="k">class</span> <span class="nc">ComplexEncoder</span><span class="p">(</span><span class="n">json</span><span class="o">.</span><span class="n">JSONEncoder</span><span class="p">):</span>
- <span class="gp">... </span> <span class="k">def</span> <span class="nf">default</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">obj</span><span class="p">):</span>
- <span class="gp">... </span> <span class="k">if</span> <span class="nb">isinstance</span><span class="p">(</span><span class="n">obj</span><span class="p">,</span> <span class="nb">complex</span><span class="p">):</span>
- <span class="gp">... </span> <span class="k">return</span> <span class="p">[</span><span class="n">obj</span><span class="o">.</span><span class="n">real</span><span class="p">,</span> <span class="n">obj</span><span class="o">.</span><span class="n">imag</span><span class="p">]</span>
- <span class="gp">... </span> <span class="c1"># Let the base class default method raise the TypeError</span>
- <span class="gp">... </span> <span class="k">return</span> <span class="nb">super</span><span class="p">()</span><span class="o">.</span><span class="n">default</span><span class="p">(</span><span class="n">obj</span><span class="p">)</span>
- <span class="gp">...</span>
- <span class="gp">>>> </span><span class="n">json</span><span class="o">.</span><span class="n">dumps</span><span class="p">(</span><span class="mi">2</span> <span class="o">+</span> <span class="mi">1</span><span class="n">j</span><span class="p">,</span> <span class="bp">cls</span><span class="o">=</span><span class="n">ComplexEncoder</span><span class="p">)</span>
- <span class="go">'[2.0, 1.0]'</span>
- <span class="gp">>>> </span><span class="n">ComplexEncoder</span><span class="p">()</span><span class="o">.</span><span class="n">encode</span><span class="p">(</span><span class="mi">2</span> <span class="o">+</span> <span class="mi">1</span><span class="n">j</span><span class="p">)</span>
- <span class="go">'[2.0, 1.0]'</span>
- <span class="gp">>>> </span><span class="nb">list</span><span class="p">(</span><span class="n">ComplexEncoder</span><span class="p">()</span><span class="o">.</span><span class="n">iterencode</span><span class="p">(</span><span class="mi">2</span> <span class="o">+</span> <span class="mi">1</span><span class="n">j</span><span class="p">))</span>
- <span class="go">['[2.0', ', 1.0', ']']</span>
- </pre></div>
- </div>
- <p>Using <a class="reference internal" href="#module-json.tool" title="json.tool: A command line to validate and pretty-print JSON."><code class="xref py py-mod docutils literal notranslate"><span class="pre">json.tool</span></code></a> from the shell to validate and pretty-print:</p>
- <div class="highlight-shell-session notranslate"><div class="highlight"><pre><span></span><span class="gp">$ </span><span class="nb">echo</span><span class="w"> </span><span class="s1">'{"json":"obj"}'</span><span class="w"> </span><span class="p">|</span><span class="w"> </span>python<span class="w"> </span>-m<span class="w"> </span>json.tool
- <span class="go">{</span>
- <span class="go"> "json": "obj"</span>
- <span class="go">}</span>
- <span class="gp">$ </span><span class="nb">echo</span><span class="w"> </span><span class="s1">'{1.2:3.4}'</span><span class="w"> </span><span class="p">|</span><span class="w"> </span>python<span class="w"> </span>-m<span class="w"> </span>json.tool
- <span class="go">Expecting property name enclosed in double quotes: line 1 column 2 (char 1)</span>
- </pre></div>
- </div>
- <p>See <a class="reference internal" href="#json-commandline"><span class="std std-ref">Command Line Interface</span></a> for detailed documentation.</p>
- <div class="admonition note">
- <p class="admonition-title">Note</p>
- <p>JSON is a subset of <a class="reference external" href="https://yaml.org/">YAML</a> 1.2. The JSON produced by
- this module’s default settings (in particular, the default <em>separators</em>
- value) is also a subset of YAML 1.0 and 1.1. This module can thus also be
- used as a YAML serializer.</p>
- </div>
- <div class="admonition note">
- <p class="admonition-title">Note</p>
- <p>This module’s encoders and decoders preserve input and output order by
- default. Order is only lost if the underlying containers are unordered.</p>
- </div>
- <section id="basic-usage">
- <h2>Basic Usage<a class="headerlink" href="#basic-usage" title="Link to this heading">¶</a></h2>
- <dl class="py function">
- <dt class="sig sig-object py" id="json.dump">
- <span class="sig-prename descclassname"><span class="pre">json.</span></span><span class="sig-name descname"><span class="pre">dump</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">obj</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">fp</span></span></em>, <em class="sig-param"><span class="o"><span class="pre">*</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">skipkeys</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">False</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">ensure_ascii</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">True</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">check_circular</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">True</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">allow_nan</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">True</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">cls</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">None</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">indent</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">None</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">separators</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">None</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">default</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">None</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">sort_keys</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">False</span></span></em>, <em class="sig-param"><span class="o"><span class="pre">**</span></span><span class="n"><span class="pre">kw</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#json.dump" title="Link to this definition">¶</a></dt>
- <dd><p>Serialize <em>obj</em> as a JSON formatted stream to <em>fp</em> (a <code class="docutils literal notranslate"><span class="pre">.write()</span></code>-supporting
- <a class="reference internal" href="../glossary.html#term-file-like-object"><span class="xref std std-term">file-like object</span></a>) using this <a class="reference internal" href="#py-to-json-table"><span class="std std-ref">conversion table</span></a>.</p>
- <p>If <em>skipkeys</em> is true (default: <code class="docutils literal notranslate"><span class="pre">False</span></code>), then dict keys that are not
- of a basic type (<a class="reference internal" href="stdtypes.html#str" title="str"><code class="xref py py-class docutils literal notranslate"><span class="pre">str</span></code></a>, <a class="reference internal" href="functions.html#int" title="int"><code class="xref py py-class docutils literal notranslate"><span class="pre">int</span></code></a>, <a class="reference internal" href="functions.html#float" title="float"><code class="xref py py-class docutils literal notranslate"><span class="pre">float</span></code></a>, <a class="reference internal" href="functions.html#bool" title="bool"><code class="xref py py-class docutils literal notranslate"><span class="pre">bool</span></code></a>,
- <code class="docutils literal notranslate"><span class="pre">None</span></code>) will be skipped instead of raising a <a class="reference internal" href="exceptions.html#TypeError" title="TypeError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">TypeError</span></code></a>.</p>
- <p>The <a class="reference internal" href="#module-json" title="json: Encode and decode the JSON format."><code class="xref py py-mod docutils literal notranslate"><span class="pre">json</span></code></a> module always produces <a class="reference internal" href="stdtypes.html#str" title="str"><code class="xref py py-class docutils literal notranslate"><span class="pre">str</span></code></a> objects, not
- <a class="reference internal" href="stdtypes.html#bytes" title="bytes"><code class="xref py py-class docutils literal notranslate"><span class="pre">bytes</span></code></a> objects. Therefore, <code class="docutils literal notranslate"><span class="pre">fp.write()</span></code> must support <a class="reference internal" href="stdtypes.html#str" title="str"><code class="xref py py-class docutils literal notranslate"><span class="pre">str</span></code></a>
- input.</p>
- <p>If <em>ensure_ascii</em> is true (the default), the output is guaranteed to
- have all incoming non-ASCII characters escaped. If <em>ensure_ascii</em> is
- false, these characters will be output as-is.</p>
- <p>If <em>check_circular</em> is false (default: <code class="docutils literal notranslate"><span class="pre">True</span></code>), then the circular
- reference check for container types will be skipped and a circular reference
- will result in a <a class="reference internal" href="exceptions.html#RecursionError" title="RecursionError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">RecursionError</span></code></a> (or worse).</p>
- <p>If <em>allow_nan</em> is false (default: <code class="docutils literal notranslate"><span class="pre">True</span></code>), then it will be a
- <a class="reference internal" href="exceptions.html#ValueError" title="ValueError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">ValueError</span></code></a> to serialize out of range <a class="reference internal" href="functions.html#float" title="float"><code class="xref py py-class docutils literal notranslate"><span class="pre">float</span></code></a> values (<code class="docutils literal notranslate"><span class="pre">nan</span></code>,
- <code class="docutils literal notranslate"><span class="pre">inf</span></code>, <code class="docutils literal notranslate"><span class="pre">-inf</span></code>) in strict compliance of the JSON specification.
- If <em>allow_nan</em> is true, their JavaScript equivalents (<code class="docutils literal notranslate"><span class="pre">NaN</span></code>,
- <code class="docutils literal notranslate"><span class="pre">Infinity</span></code>, <code class="docutils literal notranslate"><span class="pre">-Infinity</span></code>) will be used.</p>
- <p>If <em>indent</em> is a non-negative integer or string, then JSON array elements and
- object members will be pretty-printed with that indent level. An indent level
- of 0, negative, or <code class="docutils literal notranslate"><span class="pre">""</span></code> will only insert newlines. <code class="docutils literal notranslate"><span class="pre">None</span></code> (the default)
- selects the most compact representation. Using a positive integer indent
- indents that many spaces per level. If <em>indent</em> is a string (such as <code class="docutils literal notranslate"><span class="pre">"\t"</span></code>),
- that string is used to indent each level.</p>
- <div class="versionchanged">
- <p><span class="versionmodified changed">Changed in version 3.2: </span>Allow strings for <em>indent</em> in addition to integers.</p>
- </div>
- <p>If specified, <em>separators</em> should be an <code class="docutils literal notranslate"><span class="pre">(item_separator,</span> <span class="pre">key_separator)</span></code>
- tuple. The default is <code class="docutils literal notranslate"><span class="pre">(',</span> <span class="pre">',</span> <span class="pre">':</span> <span class="pre">')</span></code> if <em>indent</em> is <code class="docutils literal notranslate"><span class="pre">None</span></code> and
- <code class="docutils literal notranslate"><span class="pre">(',',</span> <span class="pre">':</span> <span class="pre">')</span></code> otherwise. To get the most compact JSON representation,
- you should specify <code class="docutils literal notranslate"><span class="pre">(',',</span> <span class="pre">':')</span></code> to eliminate whitespace.</p>
- <div class="versionchanged">
- <p><span class="versionmodified changed">Changed in version 3.4: </span>Use <code class="docutils literal notranslate"><span class="pre">(',',</span> <span class="pre">':</span> <span class="pre">')</span></code> as default if <em>indent</em> is not <code class="docutils literal notranslate"><span class="pre">None</span></code>.</p>
- </div>
- <p>If specified, <em>default</em> should be a function that gets called for objects that
- can’t otherwise be serialized. It should return a JSON encodable version of
- the object or raise a <a class="reference internal" href="exceptions.html#TypeError" title="TypeError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">TypeError</span></code></a>. If not specified, <a class="reference internal" href="exceptions.html#TypeError" title="TypeError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">TypeError</span></code></a>
- is raised.</p>
- <p>If <em>sort_keys</em> is true (default: <code class="docutils literal notranslate"><span class="pre">False</span></code>), then the output of
- dictionaries will be sorted by key.</p>
- <p>To use a custom <a class="reference internal" href="#json.JSONEncoder" title="json.JSONEncoder"><code class="xref py py-class docutils literal notranslate"><span class="pre">JSONEncoder</span></code></a> subclass (e.g. one that overrides the
- <a class="reference internal" href="#json.JSONEncoder.default" title="json.JSONEncoder.default"><code class="xref py py-meth docutils literal notranslate"><span class="pre">default()</span></code></a> method to serialize additional types), specify it with the
- <em>cls</em> kwarg; otherwise <a class="reference internal" href="#json.JSONEncoder" title="json.JSONEncoder"><code class="xref py py-class docutils literal notranslate"><span class="pre">JSONEncoder</span></code></a> is used.</p>
- <div class="versionchanged">
- <p><span class="versionmodified changed">Changed in version 3.6: </span>All optional parameters are now <a class="reference internal" href="../glossary.html#keyword-only-parameter"><span class="std std-ref">keyword-only</span></a>.</p>
- </div>
- <div class="admonition note">
- <p class="admonition-title">Note</p>
- <p>Unlike <a class="reference internal" href="pickle.html#module-pickle" title="pickle: Convert Python objects to streams of bytes and back."><code class="xref py py-mod docutils literal notranslate"><span class="pre">pickle</span></code></a> and <a class="reference internal" href="marshal.html#module-marshal" title="marshal: Convert Python objects to streams of bytes and back (with different constraints)."><code class="xref py py-mod docutils literal notranslate"><span class="pre">marshal</span></code></a>, JSON is not a framed protocol,
- so trying to serialize multiple objects with repeated calls to
- <a class="reference internal" href="#json.dump" title="json.dump"><code class="xref py py-func docutils literal notranslate"><span class="pre">dump()</span></code></a> using the same <em>fp</em> will result in an invalid JSON file.</p>
- </div>
- </dd></dl>
-
- <dl class="py function">
- <dt class="sig sig-object py" id="json.dumps">
- <span class="sig-prename descclassname"><span class="pre">json.</span></span><span class="sig-name descname"><span class="pre">dumps</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">obj</span></span></em>, <em class="sig-param"><span class="o"><span class="pre">*</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">skipkeys</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">False</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">ensure_ascii</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">True</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">check_circular</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">True</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">allow_nan</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">True</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">cls</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">None</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">indent</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">None</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">separators</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">None</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">default</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">None</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">sort_keys</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">False</span></span></em>, <em class="sig-param"><span class="o"><span class="pre">**</span></span><span class="n"><span class="pre">kw</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#json.dumps" title="Link to this definition">¶</a></dt>
- <dd><p>Serialize <em>obj</em> to a JSON formatted <a class="reference internal" href="stdtypes.html#str" title="str"><code class="xref py py-class docutils literal notranslate"><span class="pre">str</span></code></a> using this <a class="reference internal" href="#py-to-json-table"><span class="std std-ref">conversion
- table</span></a>. The arguments have the same meaning as in
- <a class="reference internal" href="#json.dump" title="json.dump"><code class="xref py py-func docutils literal notranslate"><span class="pre">dump()</span></code></a>.</p>
- <div class="admonition note">
- <p class="admonition-title">Note</p>
- <p>Keys in key/value pairs of JSON are always of the type <a class="reference internal" href="stdtypes.html#str" title="str"><code class="xref py py-class docutils literal notranslate"><span class="pre">str</span></code></a>. When
- a dictionary is converted into JSON, all the keys of the dictionary are
- coerced to strings. As a result of this, if a dictionary is converted
- into JSON and then back into a dictionary, the dictionary may not equal
- the original one. That is, <code class="docutils literal notranslate"><span class="pre">loads(dumps(x))</span> <span class="pre">!=</span> <span class="pre">x</span></code> if x has non-string
- keys.</p>
- </div>
- </dd></dl>
-
- <dl class="py function">
- <dt class="sig sig-object py" id="json.load">
- <span class="sig-prename descclassname"><span class="pre">json.</span></span><span class="sig-name descname"><span class="pre">load</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">fp</span></span></em>, <em class="sig-param"><span class="o"><span class="pre">*</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">cls</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">None</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">object_hook</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">None</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">parse_float</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">None</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">parse_int</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">None</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">parse_constant</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">None</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">object_pairs_hook</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">None</span></span></em>, <em class="sig-param"><span class="o"><span class="pre">**</span></span><span class="n"><span class="pre">kw</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#json.load" title="Link to this definition">¶</a></dt>
- <dd><p>Deserialize <em>fp</em> (a <code class="docutils literal notranslate"><span class="pre">.read()</span></code>-supporting <a class="reference internal" href="../glossary.html#term-text-file"><span class="xref std std-term">text file</span></a> or
- <a class="reference internal" href="../glossary.html#term-binary-file"><span class="xref std std-term">binary file</span></a> containing a JSON document) to a Python object using
- this <a class="reference internal" href="#json-to-py-table"><span class="std std-ref">conversion table</span></a>.</p>
- <p><em>object_hook</em> is an optional function that will be called with the result of
- any object literal decoded (a <a class="reference internal" href="stdtypes.html#dict" title="dict"><code class="xref py py-class docutils literal notranslate"><span class="pre">dict</span></code></a>). The return value of
- <em>object_hook</em> will be used instead of the <a class="reference internal" href="stdtypes.html#dict" title="dict"><code class="xref py py-class docutils literal notranslate"><span class="pre">dict</span></code></a>. This feature can be used
- to implement custom decoders (e.g. <a class="reference external" href="https://www.jsonrpc.org">JSON-RPC</a>
- class hinting).</p>
- <p><em>object_pairs_hook</em> is an optional function that will be called with the
- result of any object literal decoded with an ordered list of pairs. The
- return value of <em>object_pairs_hook</em> will be used instead of the
- <a class="reference internal" href="stdtypes.html#dict" title="dict"><code class="xref py py-class docutils literal notranslate"><span class="pre">dict</span></code></a>. This feature can be used to implement custom decoders.
- If <em>object_hook</em> is also defined, the <em>object_pairs_hook</em> takes priority.</p>
- <div class="versionchanged">
- <p><span class="versionmodified changed">Changed in version 3.1: </span>Added support for <em>object_pairs_hook</em>.</p>
- </div>
- <p><em>parse_float</em>, if specified, will be called with the string of every JSON
- float to be decoded. By default, this is equivalent to <code class="docutils literal notranslate"><span class="pre">float(num_str)</span></code>.
- This can be used to use another datatype or parser for JSON floats
- (e.g. <a class="reference internal" href="decimal.html#decimal.Decimal" title="decimal.Decimal"><code class="xref py py-class docutils literal notranslate"><span class="pre">decimal.Decimal</span></code></a>).</p>
- <p><em>parse_int</em>, if specified, will be called with the string of every JSON int
- to be decoded. By default, this is equivalent to <code class="docutils literal notranslate"><span class="pre">int(num_str)</span></code>. This can
- be used to use another datatype or parser for JSON integers
- (e.g. <a class="reference internal" href="functions.html#float" title="float"><code class="xref py py-class docutils literal notranslate"><span class="pre">float</span></code></a>).</p>
- <div class="versionchanged">
- <p><span class="versionmodified changed">Changed in version 3.11: </span>The default <em>parse_int</em> of <a class="reference internal" href="functions.html#int" title="int"><code class="xref py py-func docutils literal notranslate"><span class="pre">int()</span></code></a> now limits the maximum length of
- the integer string via the interpreter’s <a class="reference internal" href="stdtypes.html#int-max-str-digits"><span class="std std-ref">integer string
- conversion length limitation</span></a> to help avoid denial
- of service attacks.</p>
- </div>
- <p><em>parse_constant</em>, if specified, will be called with one of the following
- strings: <code class="docutils literal notranslate"><span class="pre">'-Infinity'</span></code>, <code class="docutils literal notranslate"><span class="pre">'Infinity'</span></code>, <code class="docutils literal notranslate"><span class="pre">'NaN'</span></code>.
- This can be used to raise an exception if invalid JSON numbers
- are encountered.</p>
- <div class="versionchanged">
- <p><span class="versionmodified changed">Changed in version 3.1: </span><em>parse_constant</em> doesn’t get called on ‘null’, ‘true’, ‘false’ anymore.</p>
- </div>
- <p>To use a custom <a class="reference internal" href="#json.JSONDecoder" title="json.JSONDecoder"><code class="xref py py-class docutils literal notranslate"><span class="pre">JSONDecoder</span></code></a> subclass, specify it with the <code class="docutils literal notranslate"><span class="pre">cls</span></code>
- kwarg; otherwise <a class="reference internal" href="#json.JSONDecoder" title="json.JSONDecoder"><code class="xref py py-class docutils literal notranslate"><span class="pre">JSONDecoder</span></code></a> is used. Additional keyword arguments
- will be passed to the constructor of the class.</p>
- <p>If the data being deserialized is not a valid JSON document, a
- <a class="reference internal" href="#json.JSONDecodeError" title="json.JSONDecodeError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">JSONDecodeError</span></code></a> will be raised.</p>
- <div class="versionchanged">
- <p><span class="versionmodified changed">Changed in version 3.6: </span>All optional parameters are now <a class="reference internal" href="../glossary.html#keyword-only-parameter"><span class="std std-ref">keyword-only</span></a>.</p>
- </div>
- <div class="versionchanged">
- <p><span class="versionmodified changed">Changed in version 3.6: </span><em>fp</em> can now be a <a class="reference internal" href="../glossary.html#term-binary-file"><span class="xref std std-term">binary file</span></a>. The input encoding should be
- UTF-8, UTF-16 or UTF-32.</p>
- </div>
- </dd></dl>
-
- <dl class="py function">
- <dt class="sig sig-object py" id="json.loads">
- <span class="sig-prename descclassname"><span class="pre">json.</span></span><span class="sig-name descname"><span class="pre">loads</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">s</span></span></em>, <em class="sig-param"><span class="o"><span class="pre">*</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">cls</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">None</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">object_hook</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">None</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">parse_float</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">None</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">parse_int</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">None</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">parse_constant</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">None</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">object_pairs_hook</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">None</span></span></em>, <em class="sig-param"><span class="o"><span class="pre">**</span></span><span class="n"><span class="pre">kw</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#json.loads" title="Link to this definition">¶</a></dt>
- <dd><p>Deserialize <em>s</em> (a <a class="reference internal" href="stdtypes.html#str" title="str"><code class="xref py py-class docutils literal notranslate"><span class="pre">str</span></code></a>, <a class="reference internal" href="stdtypes.html#bytes" title="bytes"><code class="xref py py-class docutils literal notranslate"><span class="pre">bytes</span></code></a> or <a class="reference internal" href="stdtypes.html#bytearray" title="bytearray"><code class="xref py py-class docutils literal notranslate"><span class="pre">bytearray</span></code></a>
- instance containing a JSON document) to a Python object using this
- <a class="reference internal" href="#json-to-py-table"><span class="std std-ref">conversion table</span></a>.</p>
- <p>The other arguments have the same meaning as in <a class="reference internal" href="#json.load" title="json.load"><code class="xref py py-func docutils literal notranslate"><span class="pre">load()</span></code></a>.</p>
- <p>If the data being deserialized is not a valid JSON document, a
- <a class="reference internal" href="#json.JSONDecodeError" title="json.JSONDecodeError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">JSONDecodeError</span></code></a> will be raised.</p>
- <div class="versionchanged">
- <p><span class="versionmodified changed">Changed in version 3.6: </span><em>s</em> can now be of type <a class="reference internal" href="stdtypes.html#bytes" title="bytes"><code class="xref py py-class docutils literal notranslate"><span class="pre">bytes</span></code></a> or <a class="reference internal" href="stdtypes.html#bytearray" title="bytearray"><code class="xref py py-class docutils literal notranslate"><span class="pre">bytearray</span></code></a>. The
- input encoding should be UTF-8, UTF-16 or UTF-32.</p>
- </div>
- <div class="versionchanged">
- <p><span class="versionmodified changed">Changed in version 3.9: </span>The keyword argument <em>encoding</em> has been removed.</p>
- </div>
- </dd></dl>
-
- </section>
- <section id="encoders-and-decoders">
- <h2>Encoders and Decoders<a class="headerlink" href="#encoders-and-decoders" title="Link to this heading">¶</a></h2>
- <dl class="py class">
- <dt class="sig sig-object py" id="json.JSONDecoder">
- <em class="property"><span class="pre">class</span><span class="w"> </span></em><span class="sig-prename descclassname"><span class="pre">json.</span></span><span class="sig-name descname"><span class="pre">JSONDecoder</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="o"><span class="pre">*</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">object_hook</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">None</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">parse_float</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">None</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">parse_int</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">None</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">parse_constant</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">None</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">strict</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">True</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">object_pairs_hook</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">None</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#json.JSONDecoder" title="Link to this definition">¶</a></dt>
- <dd><p>Simple JSON decoder.</p>
- <p>Performs the following translations in decoding by default:</p>
- <table class="docutils align-default" id="json-to-py-table">
- <thead>
- <tr class="row-odd"><th class="head"><p>JSON</p></th>
- <th class="head"><p>Python</p></th>
- </tr>
- </thead>
- <tbody>
- <tr class="row-even"><td><p>object</p></td>
- <td><p>dict</p></td>
- </tr>
- <tr class="row-odd"><td><p>array</p></td>
- <td><p>list</p></td>
- </tr>
- <tr class="row-even"><td><p>string</p></td>
- <td><p>str</p></td>
- </tr>
- <tr class="row-odd"><td><p>number (int)</p></td>
- <td><p>int</p></td>
- </tr>
- <tr class="row-even"><td><p>number (real)</p></td>
- <td><p>float</p></td>
- </tr>
- <tr class="row-odd"><td><p>true</p></td>
- <td><p>True</p></td>
- </tr>
- <tr class="row-even"><td><p>false</p></td>
- <td><p>False</p></td>
- </tr>
- <tr class="row-odd"><td><p>null</p></td>
- <td><p>None</p></td>
- </tr>
- </tbody>
- </table>
- <p>It also understands <code class="docutils literal notranslate"><span class="pre">NaN</span></code>, <code class="docutils literal notranslate"><span class="pre">Infinity</span></code>, and <code class="docutils literal notranslate"><span class="pre">-Infinity</span></code> as their
- corresponding <code class="docutils literal notranslate"><span class="pre">float</span></code> values, which is outside the JSON spec.</p>
- <p><em>object_hook</em>, if specified, will be called with the result of every JSON
- object decoded and its return value will be used in place of the given
- <a class="reference internal" href="stdtypes.html#dict" title="dict"><code class="xref py py-class docutils literal notranslate"><span class="pre">dict</span></code></a>. This can be used to provide custom deserializations (e.g. to
- support <a class="reference external" href="https://www.jsonrpc.org">JSON-RPC</a> class hinting).</p>
- <p><em>object_pairs_hook</em>, if specified will be called with the result of every
- JSON object decoded with an ordered list of pairs. The return value of
- <em>object_pairs_hook</em> will be used instead of the <a class="reference internal" href="stdtypes.html#dict" title="dict"><code class="xref py py-class docutils literal notranslate"><span class="pre">dict</span></code></a>. This
- feature can be used to implement custom decoders. If <em>object_hook</em> is also
- defined, the <em>object_pairs_hook</em> takes priority.</p>
- <div class="versionchanged">
- <p><span class="versionmodified changed">Changed in version 3.1: </span>Added support for <em>object_pairs_hook</em>.</p>
- </div>
- <p><em>parse_float</em>, if specified, will be called with the string of every JSON
- float to be decoded. By default, this is equivalent to <code class="docutils literal notranslate"><span class="pre">float(num_str)</span></code>.
- This can be used to use another datatype or parser for JSON floats
- (e.g. <a class="reference internal" href="decimal.html#decimal.Decimal" title="decimal.Decimal"><code class="xref py py-class docutils literal notranslate"><span class="pre">decimal.Decimal</span></code></a>).</p>
- <p><em>parse_int</em>, if specified, will be called with the string of every JSON int
- to be decoded. By default, this is equivalent to <code class="docutils literal notranslate"><span class="pre">int(num_str)</span></code>. This can
- be used to use another datatype or parser for JSON integers
- (e.g. <a class="reference internal" href="functions.html#float" title="float"><code class="xref py py-class docutils literal notranslate"><span class="pre">float</span></code></a>).</p>
- <p><em>parse_constant</em>, if specified, will be called with one of the following
- strings: <code class="docutils literal notranslate"><span class="pre">'-Infinity'</span></code>, <code class="docutils literal notranslate"><span class="pre">'Infinity'</span></code>, <code class="docutils literal notranslate"><span class="pre">'NaN'</span></code>.
- This can be used to raise an exception if invalid JSON numbers
- are encountered.</p>
- <p>If <em>strict</em> is false (<code class="docutils literal notranslate"><span class="pre">True</span></code> is the default), then control characters
- will be allowed inside strings. Control characters in this context are
- those with character codes in the 0–31 range, including <code class="docutils literal notranslate"><span class="pre">'\t'</span></code> (tab),
- <code class="docutils literal notranslate"><span class="pre">'\n'</span></code>, <code class="docutils literal notranslate"><span class="pre">'\r'</span></code> and <code class="docutils literal notranslate"><span class="pre">'\0'</span></code>.</p>
- <p>If the data being deserialized is not a valid JSON document, a
- <a class="reference internal" href="#json.JSONDecodeError" title="json.JSONDecodeError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">JSONDecodeError</span></code></a> will be raised.</p>
- <div class="versionchanged">
- <p><span class="versionmodified changed">Changed in version 3.6: </span>All parameters are now <a class="reference internal" href="../glossary.html#keyword-only-parameter"><span class="std std-ref">keyword-only</span></a>.</p>
- </div>
- <dl class="py method">
- <dt class="sig sig-object py" id="json.JSONDecoder.decode">
- <span class="sig-name descname"><span class="pre">decode</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">s</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#json.JSONDecoder.decode" title="Link to this definition">¶</a></dt>
- <dd><p>Return the Python representation of <em>s</em> (a <a class="reference internal" href="stdtypes.html#str" title="str"><code class="xref py py-class docutils literal notranslate"><span class="pre">str</span></code></a> instance
- containing a JSON document).</p>
- <p><a class="reference internal" href="#json.JSONDecodeError" title="json.JSONDecodeError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">JSONDecodeError</span></code></a> will be raised if the given JSON document is not
- valid.</p>
- </dd></dl>
-
- <dl class="py method">
- <dt class="sig sig-object py" id="json.JSONDecoder.raw_decode">
- <span class="sig-name descname"><span class="pre">raw_decode</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">s</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#json.JSONDecoder.raw_decode" title="Link to this definition">¶</a></dt>
- <dd><p>Decode a JSON document from <em>s</em> (a <a class="reference internal" href="stdtypes.html#str" title="str"><code class="xref py py-class docutils literal notranslate"><span class="pre">str</span></code></a> beginning with a
- JSON document) and return a 2-tuple of the Python representation
- and the index in <em>s</em> where the document ended.</p>
- <p>This can be used to decode a JSON document from a string that may have
- extraneous data at the end.</p>
- </dd></dl>
-
- </dd></dl>
-
- <dl class="py class">
- <dt class="sig sig-object py" id="json.JSONEncoder">
- <em class="property"><span class="pre">class</span><span class="w"> </span></em><span class="sig-prename descclassname"><span class="pre">json.</span></span><span class="sig-name descname"><span class="pre">JSONEncoder</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="o"><span class="pre">*</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">skipkeys</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">False</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">ensure_ascii</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">True</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">check_circular</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">True</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">allow_nan</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">True</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">sort_keys</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">False</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">indent</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">None</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">separators</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">None</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">default</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">None</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#json.JSONEncoder" title="Link to this definition">¶</a></dt>
- <dd><p>Extensible JSON encoder for Python data structures.</p>
- <p>Supports the following objects and types by default:</p>
- <table class="docutils align-default" id="py-to-json-table">
- <thead>
- <tr class="row-odd"><th class="head"><p>Python</p></th>
- <th class="head"><p>JSON</p></th>
- </tr>
- </thead>
- <tbody>
- <tr class="row-even"><td><p>dict</p></td>
- <td><p>object</p></td>
- </tr>
- <tr class="row-odd"><td><p>list, tuple</p></td>
- <td><p>array</p></td>
- </tr>
- <tr class="row-even"><td><p>str</p></td>
- <td><p>string</p></td>
- </tr>
- <tr class="row-odd"><td><p>int, float, int- & float-derived Enums</p></td>
- <td><p>number</p></td>
- </tr>
- <tr class="row-even"><td><p>True</p></td>
- <td><p>true</p></td>
- </tr>
- <tr class="row-odd"><td><p>False</p></td>
- <td><p>false</p></td>
- </tr>
- <tr class="row-even"><td><p>None</p></td>
- <td><p>null</p></td>
- </tr>
- </tbody>
- </table>
- <div class="versionchanged">
- <p><span class="versionmodified changed">Changed in version 3.4: </span>Added support for int- and float-derived Enum classes.</p>
- </div>
- <p>To extend this to recognize other objects, subclass and implement a
- <a class="reference internal" href="#json.JSONEncoder.default" title="json.JSONEncoder.default"><code class="xref py py-meth docutils literal notranslate"><span class="pre">default()</span></code></a> method with another method that returns a serializable object
- for <code class="docutils literal notranslate"><span class="pre">o</span></code> if possible, otherwise it should call the superclass implementation
- (to raise <a class="reference internal" href="exceptions.html#TypeError" title="TypeError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">TypeError</span></code></a>).</p>
- <p>If <em>skipkeys</em> is false (the default), a <a class="reference internal" href="exceptions.html#TypeError" title="TypeError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">TypeError</span></code></a> will be raised when
- trying to encode keys that are not <a class="reference internal" href="stdtypes.html#str" title="str"><code class="xref py py-class docutils literal notranslate"><span class="pre">str</span></code></a>, <a class="reference internal" href="functions.html#int" title="int"><code class="xref py py-class docutils literal notranslate"><span class="pre">int</span></code></a>, <a class="reference internal" href="functions.html#float" title="float"><code class="xref py py-class docutils literal notranslate"><span class="pre">float</span></code></a>
- or <code class="docutils literal notranslate"><span class="pre">None</span></code>. If <em>skipkeys</em> is true, such items are simply skipped.</p>
- <p>If <em>ensure_ascii</em> is true (the default), the output is guaranteed to
- have all incoming non-ASCII characters escaped. If <em>ensure_ascii</em> is
- false, these characters will be output as-is.</p>
- <p>If <em>check_circular</em> is true (the default), then lists, dicts, and custom
- encoded objects will be checked for circular references during encoding to
- prevent an infinite recursion (which would cause a <a class="reference internal" href="exceptions.html#RecursionError" title="RecursionError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">RecursionError</span></code></a>).
- Otherwise, no such check takes place.</p>
- <p>If <em>allow_nan</em> is true (the default), then <code class="docutils literal notranslate"><span class="pre">NaN</span></code>, <code class="docutils literal notranslate"><span class="pre">Infinity</span></code>, and
- <code class="docutils literal notranslate"><span class="pre">-Infinity</span></code> will be encoded as such. This behavior is not JSON
- specification compliant, but is consistent with most JavaScript based
- encoders and decoders. Otherwise, it will be a <a class="reference internal" href="exceptions.html#ValueError" title="ValueError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">ValueError</span></code></a> to encode
- such floats.</p>
- <p>If <em>sort_keys</em> is true (default: <code class="docutils literal notranslate"><span class="pre">False</span></code>), then the output of dictionaries
- will be sorted by key; this is useful for regression tests to ensure that
- JSON serializations can be compared on a day-to-day basis.</p>
- <p>If <em>indent</em> is a non-negative integer or string, then JSON array elements and
- object members will be pretty-printed with that indent level. An indent level
- of 0, negative, or <code class="docutils literal notranslate"><span class="pre">""</span></code> will only insert newlines. <code class="docutils literal notranslate"><span class="pre">None</span></code> (the default)
- selects the most compact representation. Using a positive integer indent
- indents that many spaces per level. If <em>indent</em> is a string (such as <code class="docutils literal notranslate"><span class="pre">"\t"</span></code>),
- that string is used to indent each level.</p>
- <div class="versionchanged">
- <p><span class="versionmodified changed">Changed in version 3.2: </span>Allow strings for <em>indent</em> in addition to integers.</p>
- </div>
- <p>If specified, <em>separators</em> should be an <code class="docutils literal notranslate"><span class="pre">(item_separator,</span> <span class="pre">key_separator)</span></code>
- tuple. The default is <code class="docutils literal notranslate"><span class="pre">(',</span> <span class="pre">',</span> <span class="pre">':</span> <span class="pre">')</span></code> if <em>indent</em> is <code class="docutils literal notranslate"><span class="pre">None</span></code> and
- <code class="docutils literal notranslate"><span class="pre">(',',</span> <span class="pre">':</span> <span class="pre">')</span></code> otherwise. To get the most compact JSON representation,
- you should specify <code class="docutils literal notranslate"><span class="pre">(',',</span> <span class="pre">':')</span></code> to eliminate whitespace.</p>
- <div class="versionchanged">
- <p><span class="versionmodified changed">Changed in version 3.4: </span>Use <code class="docutils literal notranslate"><span class="pre">(',',</span> <span class="pre">':</span> <span class="pre">')</span></code> as default if <em>indent</em> is not <code class="docutils literal notranslate"><span class="pre">None</span></code>.</p>
- </div>
- <p>If specified, <em>default</em> should be a function that gets called for objects that
- can’t otherwise be serialized. It should return a JSON encodable version of
- the object or raise a <a class="reference internal" href="exceptions.html#TypeError" title="TypeError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">TypeError</span></code></a>. If not specified, <a class="reference internal" href="exceptions.html#TypeError" title="TypeError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">TypeError</span></code></a>
- is raised.</p>
- <div class="versionchanged">
- <p><span class="versionmodified changed">Changed in version 3.6: </span>All parameters are now <a class="reference internal" href="../glossary.html#keyword-only-parameter"><span class="std std-ref">keyword-only</span></a>.</p>
- </div>
- <dl class="py method">
- <dt class="sig sig-object py" id="json.JSONEncoder.default">
- <span class="sig-name descname"><span class="pre">default</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">o</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#json.JSONEncoder.default" title="Link to this definition">¶</a></dt>
- <dd><p>Implement this method in a subclass such that it returns a serializable
- object for <em>o</em>, or calls the base implementation (to raise a
- <a class="reference internal" href="exceptions.html#TypeError" title="TypeError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">TypeError</span></code></a>).</p>
- <p>For example, to support arbitrary iterators, you could implement
- <a class="reference internal" href="#json.JSONEncoder.default" title="json.JSONEncoder.default"><code class="xref py py-meth docutils literal notranslate"><span class="pre">default()</span></code></a> like this:</p>
- <div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="k">def</span> <span class="nf">default</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">o</span><span class="p">):</span>
- <span class="k">try</span><span class="p">:</span>
- <span class="n">iterable</span> <span class="o">=</span> <span class="nb">iter</span><span class="p">(</span><span class="n">o</span><span class="p">)</span>
- <span class="k">except</span> <span class="ne">TypeError</span><span class="p">:</span>
- <span class="k">pass</span>
- <span class="k">else</span><span class="p">:</span>
- <span class="k">return</span> <span class="nb">list</span><span class="p">(</span><span class="n">iterable</span><span class="p">)</span>
- <span class="c1"># Let the base class default method raise the TypeError</span>
- <span class="k">return</span> <span class="nb">super</span><span class="p">()</span><span class="o">.</span><span class="n">default</span><span class="p">(</span><span class="n">o</span><span class="p">)</span>
- </pre></div>
- </div>
- </dd></dl>
-
- <dl class="py method">
- <dt class="sig sig-object py" id="json.JSONEncoder.encode">
- <span class="sig-name descname"><span class="pre">encode</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">o</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#json.JSONEncoder.encode" title="Link to this definition">¶</a></dt>
- <dd><p>Return a JSON string representation of a Python data structure, <em>o</em>. For
- example:</p>
- <div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="n">json</span><span class="o">.</span><span class="n">JSONEncoder</span><span class="p">()</span><span class="o">.</span><span class="n">encode</span><span class="p">({</span><span class="s2">"foo"</span><span class="p">:</span> <span class="p">[</span><span class="s2">"bar"</span><span class="p">,</span> <span class="s2">"baz"</span><span class="p">]})</span>
- <span class="go">'{"foo": ["bar", "baz"]}'</span>
- </pre></div>
- </div>
- </dd></dl>
-
- <dl class="py method">
- <dt class="sig sig-object py" id="json.JSONEncoder.iterencode">
- <span class="sig-name descname"><span class="pre">iterencode</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">o</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#json.JSONEncoder.iterencode" title="Link to this definition">¶</a></dt>
- <dd><p>Encode the given object, <em>o</em>, and yield each string representation as
- available. For example:</p>
- <div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="k">for</span> <span class="n">chunk</span> <span class="ow">in</span> <span class="n">json</span><span class="o">.</span><span class="n">JSONEncoder</span><span class="p">()</span><span class="o">.</span><span class="n">iterencode</span><span class="p">(</span><span class="n">bigobject</span><span class="p">):</span>
- <span class="n">mysocket</span><span class="o">.</span><span class="n">write</span><span class="p">(</span><span class="n">chunk</span><span class="p">)</span>
- </pre></div>
- </div>
- </dd></dl>
-
- </dd></dl>
-
- </section>
- <section id="exceptions">
- <h2>Exceptions<a class="headerlink" href="#exceptions" title="Link to this heading">¶</a></h2>
- <dl class="py exception">
- <dt class="sig sig-object py" id="json.JSONDecodeError">
- <em class="property"><span class="pre">exception</span><span class="w"> </span></em><span class="sig-prename descclassname"><span class="pre">json.</span></span><span class="sig-name descname"><span class="pre">JSONDecodeError</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">msg</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">doc</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">pos</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#json.JSONDecodeError" title="Link to this definition">¶</a></dt>
- <dd><p>Subclass of <a class="reference internal" href="exceptions.html#ValueError" title="ValueError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">ValueError</span></code></a> with the following additional attributes:</p>
- <dl class="py attribute">
- <dt class="sig sig-object py" id="json.JSONDecodeError.msg">
- <span class="sig-name descname"><span class="pre">msg</span></span><a class="headerlink" href="#json.JSONDecodeError.msg" title="Link to this definition">¶</a></dt>
- <dd><p>The unformatted error message.</p>
- </dd></dl>
-
- <dl class="py attribute">
- <dt class="sig sig-object py" id="json.JSONDecodeError.doc">
- <span class="sig-name descname"><span class="pre">doc</span></span><a class="headerlink" href="#json.JSONDecodeError.doc" title="Link to this definition">¶</a></dt>
- <dd><p>The JSON document being parsed.</p>
- </dd></dl>
-
- <dl class="py attribute">
- <dt class="sig sig-object py" id="json.JSONDecodeError.pos">
- <span class="sig-name descname"><span class="pre">pos</span></span><a class="headerlink" href="#json.JSONDecodeError.pos" title="Link to this definition">¶</a></dt>
- <dd><p>The start index of <em>doc</em> where parsing failed.</p>
- </dd></dl>
-
- <dl class="py attribute">
- <dt class="sig sig-object py" id="json.JSONDecodeError.lineno">
- <span class="sig-name descname"><span class="pre">lineno</span></span><a class="headerlink" href="#json.JSONDecodeError.lineno" title="Link to this definition">¶</a></dt>
- <dd><p>The line corresponding to <em>pos</em>.</p>
- </dd></dl>
-
- <dl class="py attribute">
- <dt class="sig sig-object py" id="json.JSONDecodeError.colno">
- <span class="sig-name descname"><span class="pre">colno</span></span><a class="headerlink" href="#json.JSONDecodeError.colno" title="Link to this definition">¶</a></dt>
- <dd><p>The column corresponding to <em>pos</em>.</p>
- </dd></dl>
-
- <div class="versionadded">
- <p><span class="versionmodified added">New in version 3.5.</span></p>
- </div>
- </dd></dl>
-
- </section>
- <section id="standard-compliance-and-interoperability">
- <h2>Standard Compliance and Interoperability<a class="headerlink" href="#standard-compliance-and-interoperability" title="Link to this heading">¶</a></h2>
- <p>The JSON format is specified by <span class="target" id="index-2"></span><a class="rfc reference external" href="https://datatracker.ietf.org/doc/html/rfc7159.html"><strong>RFC 7159</strong></a> and by
- <a class="reference external" href="https://www.ecma-international.org/publications-and-standards/standards/ecma-404/">ECMA-404</a>.
- This section details this module’s level of compliance with the RFC.
- For simplicity, <a class="reference internal" href="#json.JSONEncoder" title="json.JSONEncoder"><code class="xref py py-class docutils literal notranslate"><span class="pre">JSONEncoder</span></code></a> and <a class="reference internal" href="#json.JSONDecoder" title="json.JSONDecoder"><code class="xref py py-class docutils literal notranslate"><span class="pre">JSONDecoder</span></code></a> subclasses, and
- parameters other than those explicitly mentioned, are not considered.</p>
- <p>This module does not comply with the RFC in a strict fashion, implementing some
- extensions that are valid JavaScript but not valid JSON. In particular:</p>
- <ul class="simple">
- <li><p>Infinite and NaN number values are accepted and output;</p></li>
- <li><p>Repeated names within an object are accepted, and only the value of the last
- name-value pair is used.</p></li>
- </ul>
- <p>Since the RFC permits RFC-compliant parsers to accept input texts that are not
- RFC-compliant, this module’s deserializer is technically RFC-compliant under
- default settings.</p>
- <section id="character-encodings">
- <h3>Character Encodings<a class="headerlink" href="#character-encodings" title="Link to this heading">¶</a></h3>
- <p>The RFC requires that JSON be represented using either UTF-8, UTF-16, or
- UTF-32, with UTF-8 being the recommended default for maximum interoperability.</p>
- <p>As permitted, though not required, by the RFC, this module’s serializer sets
- <em>ensure_ascii=True</em> by default, thus escaping the output so that the resulting
- strings only contain ASCII characters.</p>
- <p>Other than the <em>ensure_ascii</em> parameter, this module is defined strictly in
- terms of conversion between Python objects and
- <a class="reference internal" href="stdtypes.html#str" title="str"><code class="xref py py-class docutils literal notranslate"><span class="pre">Unicode</span> <span class="pre">strings</span></code></a>, and thus does not otherwise directly address
- the issue of character encodings.</p>
- <p>The RFC prohibits adding a byte order mark (BOM) to the start of a JSON text,
- and this module’s serializer does not add a BOM to its output.
- The RFC permits, but does not require, JSON deserializers to ignore an initial
- BOM in their input. This module’s deserializer raises a <a class="reference internal" href="exceptions.html#ValueError" title="ValueError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">ValueError</span></code></a>
- when an initial BOM is present.</p>
- <p>The RFC does not explicitly forbid JSON strings which contain byte sequences
- that don’t correspond to valid Unicode characters (e.g. unpaired UTF-16
- surrogates), but it does note that they may cause interoperability problems.
- By default, this module accepts and outputs (when present in the original
- <a class="reference internal" href="stdtypes.html#str" title="str"><code class="xref py py-class docutils literal notranslate"><span class="pre">str</span></code></a>) code points for such sequences.</p>
- </section>
- <section id="infinite-and-nan-number-values">
- <h3>Infinite and NaN Number Values<a class="headerlink" href="#infinite-and-nan-number-values" title="Link to this heading">¶</a></h3>
- <p>The RFC does not permit the representation of infinite or NaN number values.
- Despite that, by default, this module accepts and outputs <code class="docutils literal notranslate"><span class="pre">Infinity</span></code>,
- <code class="docutils literal notranslate"><span class="pre">-Infinity</span></code>, and <code class="docutils literal notranslate"><span class="pre">NaN</span></code> as if they were valid JSON number literal values:</p>
- <div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="c1"># Neither of these calls raises an exception, but the results are not valid JSON</span>
- <span class="gp">>>> </span><span class="n">json</span><span class="o">.</span><span class="n">dumps</span><span class="p">(</span><span class="nb">float</span><span class="p">(</span><span class="s1">'-inf'</span><span class="p">))</span>
- <span class="go">'-Infinity'</span>
- <span class="gp">>>> </span><span class="n">json</span><span class="o">.</span><span class="n">dumps</span><span class="p">(</span><span class="nb">float</span><span class="p">(</span><span class="s1">'nan'</span><span class="p">))</span>
- <span class="go">'NaN'</span>
- <span class="gp">>>> </span><span class="c1"># Same when deserializing</span>
- <span class="gp">>>> </span><span class="n">json</span><span class="o">.</span><span class="n">loads</span><span class="p">(</span><span class="s1">'-Infinity'</span><span class="p">)</span>
- <span class="go">-inf</span>
- <span class="gp">>>> </span><span class="n">json</span><span class="o">.</span><span class="n">loads</span><span class="p">(</span><span class="s1">'NaN'</span><span class="p">)</span>
- <span class="go">nan</span>
- </pre></div>
- </div>
- <p>In the serializer, the <em>allow_nan</em> parameter can be used to alter this
- behavior. In the deserializer, the <em>parse_constant</em> parameter can be used to
- alter this behavior.</p>
- </section>
- <section id="repeated-names-within-an-object">
- <h3>Repeated Names Within an Object<a class="headerlink" href="#repeated-names-within-an-object" title="Link to this heading">¶</a></h3>
- <p>The RFC specifies that the names within a JSON object should be unique, but
- does not mandate how repeated names in JSON objects should be handled. By
- default, this module does not raise an exception; instead, it ignores all but
- the last name-value pair for a given name:</p>
- <div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="gp">>>> </span><span class="n">weird_json</span> <span class="o">=</span> <span class="s1">'{"x": 1, "x": 2, "x": 3}'</span>
- <span class="gp">>>> </span><span class="n">json</span><span class="o">.</span><span class="n">loads</span><span class="p">(</span><span class="n">weird_json</span><span class="p">)</span>
- <span class="go">{'x': 3}</span>
- </pre></div>
- </div>
- <p>The <em>object_pairs_hook</em> parameter can be used to alter this behavior.</p>
- </section>
- <section id="top-level-non-object-non-array-values">
- <h3>Top-level Non-Object, Non-Array Values<a class="headerlink" href="#top-level-non-object-non-array-values" title="Link to this heading">¶</a></h3>
- <p>The old version of JSON specified by the obsolete <span class="target" id="index-3"></span><a class="rfc reference external" href="https://datatracker.ietf.org/doc/html/rfc4627.html"><strong>RFC 4627</strong></a> required that
- the top-level value of a JSON text must be either a JSON object or array
- (Python <a class="reference internal" href="stdtypes.html#dict" title="dict"><code class="xref py py-class docutils literal notranslate"><span class="pre">dict</span></code></a> or <a class="reference internal" href="stdtypes.html#list" title="list"><code class="xref py py-class docutils literal notranslate"><span class="pre">list</span></code></a>), and could not be a JSON null,
- boolean, number, or string value. <span class="target" id="index-4"></span><a class="rfc reference external" href="https://datatracker.ietf.org/doc/html/rfc7159.html"><strong>RFC 7159</strong></a> removed that restriction, and
- this module does not and has never implemented that restriction in either its
- serializer or its deserializer.</p>
- <p>Regardless, for maximum interoperability, you may wish to voluntarily adhere
- to the restriction yourself.</p>
- </section>
- <section id="implementation-limitations">
- <h3>Implementation Limitations<a class="headerlink" href="#implementation-limitations" title="Link to this heading">¶</a></h3>
- <p>Some JSON deserializer implementations may set limits on:</p>
- <ul class="simple">
- <li><p>the size of accepted JSON texts</p></li>
- <li><p>the maximum level of nesting of JSON objects and arrays</p></li>
- <li><p>the range and precision of JSON numbers</p></li>
- <li><p>the content and maximum length of JSON strings</p></li>
- </ul>
- <p>This module does not impose any such limits beyond those of the relevant
- Python datatypes themselves or the Python interpreter itself.</p>
- <p>When serializing to JSON, beware any such limitations in applications that may
- consume your JSON. In particular, it is common for JSON numbers to be
- deserialized into IEEE 754 double precision numbers and thus subject to that
- representation’s range and precision limitations. This is especially relevant
- when serializing Python <a class="reference internal" href="functions.html#int" title="int"><code class="xref py py-class docutils literal notranslate"><span class="pre">int</span></code></a> values of extremely large magnitude, or
- when serializing instances of “exotic” numerical types such as
- <a class="reference internal" href="decimal.html#decimal.Decimal" title="decimal.Decimal"><code class="xref py py-class docutils literal notranslate"><span class="pre">decimal.Decimal</span></code></a>.</p>
- </section>
- </section>
- <section id="module-json.tool">
- <span id="command-line-interface"></span><span id="json-commandline"></span><h2>Command Line Interface<a class="headerlink" href="#module-json.tool" title="Link to this heading">¶</a></h2>
- <p><strong>Source code:</strong> <a class="reference external" href="https://github.com/python/cpython/tree/3.12/Lib/json/tool.py">Lib/json/tool.py</a></p>
- <hr class="docutils" />
- <p>The <a class="reference internal" href="#module-json.tool" title="json.tool: A command line to validate and pretty-print JSON."><code class="xref py py-mod docutils literal notranslate"><span class="pre">json.tool</span></code></a> module provides a simple command line interface to validate
- and pretty-print JSON objects.</p>
- <p>If the optional <code class="docutils literal notranslate"><span class="pre">infile</span></code> and <code class="docutils literal notranslate"><span class="pre">outfile</span></code> arguments are not
- specified, <a class="reference internal" href="sys.html#sys.stdin" title="sys.stdin"><code class="xref py py-data docutils literal notranslate"><span class="pre">sys.stdin</span></code></a> and <a class="reference internal" href="sys.html#sys.stdout" title="sys.stdout"><code class="xref py py-data docutils literal notranslate"><span class="pre">sys.stdout</span></code></a> will be used respectively:</p>
- <div class="highlight-shell-session notranslate"><div class="highlight"><pre><span></span><span class="gp">$ </span><span class="nb">echo</span><span class="w"> </span><span class="s1">'{"json": "obj"}'</span><span class="w"> </span><span class="p">|</span><span class="w"> </span>python<span class="w"> </span>-m<span class="w"> </span>json.tool
- <span class="go">{</span>
- <span class="go"> "json": "obj"</span>
- <span class="go">}</span>
- <span class="gp">$ </span><span class="nb">echo</span><span class="w"> </span><span class="s1">'{1.2:3.4}'</span><span class="w"> </span><span class="p">|</span><span class="w"> </span>python<span class="w"> </span>-m<span class="w"> </span>json.tool
- <span class="go">Expecting property name enclosed in double quotes: line 1 column 2 (char 1)</span>
- </pre></div>
- </div>
- <div class="versionchanged">
- <p><span class="versionmodified changed">Changed in version 3.5: </span>The output is now in the same order as the input. Use the
- <a class="reference internal" href="#cmdoption-json.tool-sort-keys"><code class="xref std std-option docutils literal notranslate"><span class="pre">--sort-keys</span></code></a> option to sort the output of dictionaries
- alphabetically by key.</p>
- </div>
- <section id="command-line-options">
- <h3>Command line options<a class="headerlink" href="#command-line-options" title="Link to this heading">¶</a></h3>
- <dl class="std option">
- <dt class="sig sig-object std" id="cmdoption-json.tool-arg-infile">
- <span class="sig-name descname"><span class="pre">infile</span></span><span class="sig-prename descclassname"></span><a class="headerlink" href="#cmdoption-json.tool-arg-infile" title="Link to this definition">¶</a></dt>
- <dd><p>The JSON file to be validated or pretty-printed:</p>
- <div class="highlight-shell-session notranslate"><div class="highlight"><pre><span></span><span class="gp">$ </span>python<span class="w"> </span>-m<span class="w"> </span>json.tool<span class="w"> </span>mp_films.json
- <span class="go">[</span>
- <span class="go"> {</span>
- <span class="go"> "title": "And Now for Something Completely Different",</span>
- <span class="go"> "year": 1971</span>
- <span class="go"> },</span>
- <span class="go"> {</span>
- <span class="go"> "title": "Monty Python and the Holy Grail",</span>
- <span class="go"> "year": 1975</span>
- <span class="go"> }</span>
- <span class="go">]</span>
- </pre></div>
- </div>
- <p>If <em>infile</em> is not specified, read from <a class="reference internal" href="sys.html#sys.stdin" title="sys.stdin"><code class="xref py py-data docutils literal notranslate"><span class="pre">sys.stdin</span></code></a>.</p>
- </dd></dl>
-
- <dl class="std option">
- <dt class="sig sig-object std" id="cmdoption-json.tool-arg-outfile">
- <span class="sig-name descname"><span class="pre">outfile</span></span><span class="sig-prename descclassname"></span><a class="headerlink" href="#cmdoption-json.tool-arg-outfile" title="Link to this definition">¶</a></dt>
- <dd><p>Write the output of the <em>infile</em> to the given <em>outfile</em>. Otherwise, write it
- to <a class="reference internal" href="sys.html#sys.stdout" title="sys.stdout"><code class="xref py py-data docutils literal notranslate"><span class="pre">sys.stdout</span></code></a>.</p>
- </dd></dl>
-
- <dl class="std option">
- <dt class="sig sig-object std" id="cmdoption-json.tool-sort-keys">
- <span class="sig-name descname"><span class="pre">--sort-keys</span></span><span class="sig-prename descclassname"></span><a class="headerlink" href="#cmdoption-json.tool-sort-keys" title="Link to this definition">¶</a></dt>
- <dd><p>Sort the output of dictionaries alphabetically by key.</p>
- <div class="versionadded">
- <p><span class="versionmodified added">New in version 3.5.</span></p>
- </div>
- </dd></dl>
-
- <dl class="std option">
- <dt class="sig sig-object std" id="cmdoption-json.tool-no-ensure-ascii">
- <span class="sig-name descname"><span class="pre">--no-ensure-ascii</span></span><span class="sig-prename descclassname"></span><a class="headerlink" href="#cmdoption-json.tool-no-ensure-ascii" title="Link to this definition">¶</a></dt>
- <dd><p>Disable escaping of non-ascii characters, see <a class="reference internal" href="#json.dumps" title="json.dumps"><code class="xref py py-func docutils literal notranslate"><span class="pre">json.dumps()</span></code></a> for more information.</p>
- <div class="versionadded">
- <p><span class="versionmodified added">New in version 3.9.</span></p>
- </div>
- </dd></dl>
-
- <dl class="std option">
- <dt class="sig sig-object std" id="cmdoption-json.tool-json-lines">
- <span class="sig-name descname"><span class="pre">--json-lines</span></span><span class="sig-prename descclassname"></span><a class="headerlink" href="#cmdoption-json.tool-json-lines" title="Link to this definition">¶</a></dt>
- <dd><p>Parse every input line as separate JSON object.</p>
- <div class="versionadded">
- <p><span class="versionmodified added">New in version 3.8.</span></p>
- </div>
- </dd></dl>
-
- <dl class="std option">
- <dt class="sig sig-object std" id="cmdoption-json.tool-indent">
- <span id="cmdoption-json.tool-tab"></span><span id="cmdoption-json.tool-no-indent"></span><span id="cmdoption-json.tool-compact"></span><span class="sig-name descname"><span class="pre">--indent</span></span><span class="sig-prename descclassname"></span><span class="sig-prename descclassname"><span class="pre">,</span> </span><span class="sig-name descname"><span class="pre">--tab</span></span><span class="sig-prename descclassname"></span><span class="sig-prename descclassname"><span class="pre">,</span> </span><span class="sig-name descname"><span class="pre">--no-indent</span></span><span class="sig-prename descclassname"></span><span class="sig-prename descclassname"><span class="pre">,</span> </span><span class="sig-name descname"><span class="pre">--compact</span></span><span class="sig-prename descclassname"></span><a class="headerlink" href="#cmdoption-json.tool-indent" title="Link to this definition">¶</a></dt>
- <dd><p>Mutually exclusive options for whitespace control.</p>
- <div class="versionadded">
- <p><span class="versionmodified added">New in version 3.9.</span></p>
- </div>
- </dd></dl>
-
- <dl class="std option">
- <dt class="sig sig-object std" id="cmdoption-json.tool-h">
- <span id="cmdoption-json.tool-help"></span><span class="sig-name descname"><span class="pre">-h</span></span><span class="sig-prename descclassname"></span><span class="sig-prename descclassname"><span class="pre">,</span> </span><span class="sig-name descname"><span class="pre">--help</span></span><span class="sig-prename descclassname"></span><a class="headerlink" href="#cmdoption-json.tool-h" title="Link to this definition">¶</a></dt>
- <dd><p>Show the help message.</p>
- </dd></dl>
-
- <p class="rubric">Footnotes</p>
- <aside class="footnote-list brackets">
- <aside class="footnote brackets" id="rfc-errata" role="doc-footnote">
- <span class="label"><span class="fn-bracket">[</span><a role="doc-backlink" href="#id1">1</a><span class="fn-bracket">]</span></span>
- <p>As noted in <a class="reference external" href="https://www.rfc-editor.org/errata_search.php?rfc=7159">the errata for RFC 7159</a>,
- JSON permits literal U+2028 (LINE SEPARATOR) and
- U+2029 (PARAGRAPH SEPARATOR) characters in strings, whereas JavaScript
- (as of ECMAScript Edition 5.1) does not.</p>
- </aside>
- </aside>
- </section>
- </section>
- </section>
-
-
- <div class="clearer"></div>
- </div>
- </div>
- </div>
- <div class="sphinxsidebar" role="navigation" aria-label="main navigation">
- <div class="sphinxsidebarwrapper">
- <div>
- <h3><a href="../contents.html">Table of Contents</a></h3>
- <ul>
- <li><a class="reference internal" href="#"><code class="xref py py-mod docutils literal notranslate"><span class="pre">json</span></code> — JSON encoder and decoder</a><ul>
- <li><a class="reference internal" href="#basic-usage">Basic Usage</a></li>
- <li><a class="reference internal" href="#encoders-and-decoders">Encoders and Decoders</a></li>
- <li><a class="reference internal" href="#exceptions">Exceptions</a></li>
- <li><a class="reference internal" href="#standard-compliance-and-interoperability">Standard Compliance and Interoperability</a><ul>
- <li><a class="reference internal" href="#character-encodings">Character Encodings</a></li>
- <li><a class="reference internal" href="#infinite-and-nan-number-values">Infinite and NaN Number Values</a></li>
- <li><a class="reference internal" href="#repeated-names-within-an-object">Repeated Names Within an Object</a></li>
- <li><a class="reference internal" href="#top-level-non-object-non-array-values">Top-level Non-Object, Non-Array Values</a></li>
- <li><a class="reference internal" href="#implementation-limitations">Implementation Limitations</a></li>
- </ul>
- </li>
- <li><a class="reference internal" href="#module-json.tool">Command Line Interface</a><ul>
- <li><a class="reference internal" href="#command-line-options">Command line options</a></li>
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