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  99. <li><a class="reference internal" href="#repr-objects">Repr Objects</a></li>

  100. <li><a class="reference internal" href="#subclassing-repr-objects">Subclassing Repr Objects</a></li>

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  193.   <section id="module-reprlib">

  194. <span id="reprlib-alternate-repr-implementation"></span><h1><a class="reference internal" href="#module-reprlib" title="reprlib: Alternate repr() implementation with size limits."><code class="xref py py-mod docutils literal notranslate"><span class="pre">reprlib</span></code></a> — Alternate <a class="reference internal" href="functions.html#repr" title="repr"><code class="xref py py-func docutils literal notranslate"><span class="pre">repr()</span></code></a> implementation<a class="headerlink" href="#module-reprlib" title="Link to this heading">¶</a></h1>

  195. <p><strong>Source code:</strong> <a class="reference external" href="https://github.com/python/cpython/tree/3.12/Lib/reprlib.py">Lib/reprlib.py</a></p>

  196. <hr class="docutils" />

  197. <p>The <code class="xref py py-mod docutils literal notranslate"><span class="pre">reprlib</span></code> module provides a means for producing object representations

  198. with limits on the size of the resulting strings. This is used in the Python

  199. debugger and may be useful in other contexts as well.</p>

  200. <p>This module provides a class, an instance, and a function:</p>

  201. <dl class="py class">

  202. <dt class="sig sig-object py" id="reprlib.Repr">

  203. <em class="property"><span class="pre">class</span><span class="w"> </span></em><span class="sig-prename descclassname"><span class="pre">reprlib.</span></span><span class="sig-name descname"><span class="pre">Repr</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">maxlevel</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">6</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">maxtuple</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">6</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">maxlist</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">6</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">maxarray</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">5</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">maxdict</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">4</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">maxset</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">6</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">maxfrozenset</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">6</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">maxdeque</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">6</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">maxstring</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">30</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">maxlong</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">40</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">maxother</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">30</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">fillvalue</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">'...'</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><span class="sig-paren">)</span><a class="headerlink" href="#reprlib.Repr" title="Link to this definition">¶</a></dt>

  204. <dd><p>Class which provides formatting services useful in implementing functions

  205. similar to the built-in <a class="reference internal" href="functions.html#repr" title="repr"><code class="xref py py-func docutils literal notranslate"><span class="pre">repr()</span></code></a>; size limits for  different object types

  206. are added to avoid the generation of representations which are excessively long.</p>

  207. <p>The keyword arguments of the constructor can be used as a shortcut to set the

  208. attributes of the <a class="reference internal" href="#reprlib.Repr" title="reprlib.Repr"><code class="xref py py-class docutils literal notranslate"><span class="pre">Repr</span></code></a> instance. Which means that the following

  209. initialization:</p>

  210. <div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="n">aRepr</span> <span class="o">=</span> <span class="n">reprlib</span><span class="o">.</span><span class="n">Repr</span><span class="p">(</span><span class="n">maxlevel</span><span class="o">=</span><span class="mi">3</span><span class="p">)</span>

  211. </pre></div>

  212. </div>

  213. <p>Is equivalent to:</p>

  214. <div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="n">aRepr</span> <span class="o">=</span> <span class="n">reprlib</span><span class="o">.</span><span class="n">Repr</span><span class="p">()</span>

  215. <span class="n">aRepr</span><span class="o">.</span><span class="n">maxlevel</span> <span class="o">=</span> <span class="mi">3</span>

  216. </pre></div>

  217. </div>

  218. <p>See section <a class="reference internal" href="#id1">Repr Objects</a> for more information about <a class="reference internal" href="#reprlib.Repr" title="reprlib.Repr"><code class="xref py py-class docutils literal notranslate"><span class="pre">Repr</span></code></a>

  219. attributes.</p>

  220. <div class="versionchanged">

  221. <p><span class="versionmodified changed">Changed in version 3.12: </span>Allow attributes to be set via keyword arguments.</p>

  222. </div>

  223. </dd></dl>

  224. 

  225. <dl class="py data">

  226. <dt class="sig sig-object py" id="reprlib.aRepr">

  227. <span class="sig-prename descclassname"><span class="pre">reprlib.</span></span><span class="sig-name descname"><span class="pre">aRepr</span></span><a class="headerlink" href="#reprlib.aRepr" title="Link to this definition">¶</a></dt>

  228. <dd><p>This is an instance of <a class="reference internal" href="#reprlib.Repr" title="reprlib.Repr"><code class="xref py py-class docutils literal notranslate"><span class="pre">Repr</span></code></a> which is used to provide the

  229. <a class="reference internal" href="#reprlib.repr" title="reprlib.repr"><code class="xref py py-func docutils literal notranslate"><span class="pre">repr()</span></code></a> function described below.  Changing the attributes of this

  230. object will affect the size limits used by <a class="reference internal" href="#reprlib.repr" title="reprlib.repr"><code class="xref py py-func docutils literal notranslate"><span class="pre">repr()</span></code></a> and the Python

  231. debugger.</p>

  232. </dd></dl>

  233. 

  234. <dl class="py function">

  235. <dt class="sig sig-object py" id="reprlib.repr">

  236. <span class="sig-prename descclassname"><span class="pre">reprlib.</span></span><span class="sig-name descname"><span class="pre">repr</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">obj</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#reprlib.repr" title="Link to this definition">¶</a></dt>

  237. <dd><p>This is the <a class="reference internal" href="#reprlib.Repr.repr" title="reprlib.Repr.repr"><code class="xref py py-meth docutils literal notranslate"><span class="pre">repr()</span></code></a> method of <code class="docutils literal notranslate"><span class="pre">aRepr</span></code>.  It returns a string

  238. similar to that returned by the built-in function of the same name, but with

  239. limits on most sizes.</p>

  240. </dd></dl>

  241. 

  242. <p>In addition to size-limiting tools, the module also provides a decorator for

  243. detecting recursive calls to <a class="reference internal" href="../reference/datamodel.html#object.__repr__" title="object.__repr__"><code class="xref py py-meth docutils literal notranslate"><span class="pre">__repr__()</span></code></a> and substituting a

  244. placeholder string instead.</p>

  245. <dl class="py function" id="index-0">

  246. <dt class="sig sig-object py" id="reprlib.recursive_repr">

  247. <span class="sig-prename descclassname"><span class="pre">&#64;</span></span><span class="sig-prename descclassname"><span class="pre">reprlib.</span></span><span class="sig-name descname"><span class="pre">recursive_repr</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">fillvalue</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">'...'</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#reprlib.recursive_repr" title="Link to this definition">¶</a></dt>

  248. <dd><p>Decorator for <a class="reference internal" href="../reference/datamodel.html#object.__repr__" title="object.__repr__"><code class="xref py py-meth docutils literal notranslate"><span class="pre">__repr__()</span></code></a> methods to detect recursive calls within the

  249. same thread.  If a recursive call is made, the <em>fillvalue</em> is returned,

  250. otherwise, the usual <code class="xref py py-meth docutils literal notranslate"><span class="pre">__repr__()</span></code> call is made.  For example:</p>

  251. <div class="highlight-pycon notranslate"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="kn">from</span> <span class="nn">reprlib</span> <span class="kn">import</span> <span class="n">recursive_repr</span>

  252. <span class="gp">&gt;&gt;&gt; </span><span class="k">class</span> <span class="nc">MyList</span><span class="p">(</span><span class="nb">list</span><span class="p">):</span>

  253. <span class="gp">... </span>    <span class="nd">@recursive_repr</span><span class="p">()</span>

  254. <span class="gp">... </span>    <span class="k">def</span> <span class="fm">__repr__</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>

  255. <span class="gp">... </span>        <span class="k">return</span> <span class="s1">&#39;&lt;&#39;</span> <span class="o">+</span> <span class="s1">&#39;|&#39;</span><span class="o">.</span><span class="n">join</span><span class="p">(</span><span class="nb">map</span><span class="p">(</span><span class="nb">repr</span><span class="p">,</span> <span class="bp">self</span><span class="p">))</span> <span class="o">+</span> <span class="s1">&#39;&gt;&#39;</span>

  256. <span class="gp">...</span>

  257. <span class="gp">&gt;&gt;&gt; </span><span class="n">m</span> <span class="o">=</span> <span class="n">MyList</span><span class="p">(</span><span class="s1">&#39;abc&#39;</span><span class="p">)</span>

  258. <span class="gp">&gt;&gt;&gt; </span><span class="n">m</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="n">m</span><span class="p">)</span>

  259. <span class="gp">&gt;&gt;&gt; </span><span class="n">m</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="s1">&#39;x&#39;</span><span class="p">)</span>

  260. <span class="gp">&gt;&gt;&gt; </span><span class="nb">print</span><span class="p">(</span><span class="n">m</span><span class="p">)</span>

  261. <span class="go">&lt;&#39;a&#39;|&#39;b&#39;|&#39;c&#39;|...|&#39;x&#39;&gt;</span>

  262. </pre></div>

  263. </div>

  264. <div class="versionadded">

  265. <p><span class="versionmodified added">New in version 3.2.</span></p>

  266. </div>

  267. </dd></dl>

  268. 

  269. <section id="repr-objects">

  270. <span id="id1"></span><h2>Repr Objects<a class="headerlink" href="#repr-objects" title="Link to this heading">¶</a></h2>

  271. <p><a class="reference internal" href="#reprlib.Repr" title="reprlib.Repr"><code class="xref py py-class docutils literal notranslate"><span class="pre">Repr</span></code></a> instances provide several attributes which can be used to provide

  272. size limits for the representations of different object types,  and methods

  273. which format specific object types.</p>

  274. <dl class="py attribute">

  275. <dt class="sig sig-object py" id="reprlib.Repr.fillvalue">

  276. <span class="sig-prename descclassname"><span class="pre">Repr.</span></span><span class="sig-name descname"><span class="pre">fillvalue</span></span><a class="headerlink" href="#reprlib.Repr.fillvalue" title="Link to this definition">¶</a></dt>

  277. <dd><p>This string is displayed for recursive references. It defaults to

  278. <code class="docutils literal notranslate"><span class="pre">...</span></code>.</p>

  279. <div class="versionadded">

  280. <p><span class="versionmodified added">New in version 3.11.</span></p>

  281. </div>

  282. </dd></dl>

  283. 

  284. <dl class="py attribute">

  285. <dt class="sig sig-object py" id="reprlib.Repr.maxlevel">

  286. <span class="sig-prename descclassname"><span class="pre">Repr.</span></span><span class="sig-name descname"><span class="pre">maxlevel</span></span><a class="headerlink" href="#reprlib.Repr.maxlevel" title="Link to this definition">¶</a></dt>

  287. <dd><p>Depth limit on the creation of recursive representations.  The default is <code class="docutils literal notranslate"><span class="pre">6</span></code>.</p>

  288. </dd></dl>

  289. 

  290. <dl class="py attribute">

  291. <dt class="sig sig-object py" id="reprlib.Repr.maxdict">

  292. <span class="sig-prename descclassname"><span class="pre">Repr.</span></span><span class="sig-name descname"><span class="pre">maxdict</span></span><a class="headerlink" href="#reprlib.Repr.maxdict" title="Link to this definition">¶</a></dt>

  293. <dt class="sig sig-object py" id="reprlib.Repr.maxlist">

  294. <span class="sig-prename descclassname"><span class="pre">Repr.</span></span><span class="sig-name descname"><span class="pre">maxlist</span></span><a class="headerlink" href="#reprlib.Repr.maxlist" title="Link to this definition">¶</a></dt>

  295. <dt class="sig sig-object py" id="reprlib.Repr.maxtuple">

  296. <span class="sig-prename descclassname"><span class="pre">Repr.</span></span><span class="sig-name descname"><span class="pre">maxtuple</span></span><a class="headerlink" href="#reprlib.Repr.maxtuple" title="Link to this definition">¶</a></dt>

  297. <dt class="sig sig-object py" id="reprlib.Repr.maxset">

  298. <span class="sig-prename descclassname"><span class="pre">Repr.</span></span><span class="sig-name descname"><span class="pre">maxset</span></span><a class="headerlink" href="#reprlib.Repr.maxset" title="Link to this definition">¶</a></dt>

  299. <dt class="sig sig-object py" id="reprlib.Repr.maxfrozenset">

  300. <span class="sig-prename descclassname"><span class="pre">Repr.</span></span><span class="sig-name descname"><span class="pre">maxfrozenset</span></span><a class="headerlink" href="#reprlib.Repr.maxfrozenset" title="Link to this definition">¶</a></dt>

  301. <dt class="sig sig-object py" id="reprlib.Repr.maxdeque">

  302. <span class="sig-prename descclassname"><span class="pre">Repr.</span></span><span class="sig-name descname"><span class="pre">maxdeque</span></span><a class="headerlink" href="#reprlib.Repr.maxdeque" title="Link to this definition">¶</a></dt>

  303. <dt class="sig sig-object py" id="reprlib.Repr.maxarray">

  304. <span class="sig-prename descclassname"><span class="pre">Repr.</span></span><span class="sig-name descname"><span class="pre">maxarray</span></span><a class="headerlink" href="#reprlib.Repr.maxarray" title="Link to this definition">¶</a></dt>

  305. <dd><p>Limits on the number of entries represented for the named object type.  The

  306. default is <code class="docutils literal notranslate"><span class="pre">4</span></code> for <a class="reference internal" href="#reprlib.Repr.maxdict" title="reprlib.Repr.maxdict"><code class="xref py py-attr docutils literal notranslate"><span class="pre">maxdict</span></code></a>, <code class="docutils literal notranslate"><span class="pre">5</span></code> for <a class="reference internal" href="#reprlib.Repr.maxarray" title="reprlib.Repr.maxarray"><code class="xref py py-attr docutils literal notranslate"><span class="pre">maxarray</span></code></a>, and  <code class="docutils literal notranslate"><span class="pre">6</span></code> for

  307. the others.</p>

  308. </dd></dl>

  309. 

  310. <dl class="py attribute">

  311. <dt class="sig sig-object py" id="reprlib.Repr.maxlong">

  312. <span class="sig-prename descclassname"><span class="pre">Repr.</span></span><span class="sig-name descname"><span class="pre">maxlong</span></span><a class="headerlink" href="#reprlib.Repr.maxlong" title="Link to this definition">¶</a></dt>

  313. <dd><p>Maximum number of characters in the representation for an integer.  Digits

  314. are dropped from the middle.  The default is <code class="docutils literal notranslate"><span class="pre">40</span></code>.</p>

  315. </dd></dl>

  316. 

  317. <dl class="py attribute">

  318. <dt class="sig sig-object py" id="reprlib.Repr.maxstring">

  319. <span class="sig-prename descclassname"><span class="pre">Repr.</span></span><span class="sig-name descname"><span class="pre">maxstring</span></span><a class="headerlink" href="#reprlib.Repr.maxstring" title="Link to this definition">¶</a></dt>

  320. <dd><p>Limit on the number of characters in the representation of the string.  Note

  321. that the “normal” representation of the string is used as the character source:

  322. if escape sequences are needed in the representation, these may be mangled when

  323. the representation is shortened.  The default is <code class="docutils literal notranslate"><span class="pre">30</span></code>.</p>

  324. </dd></dl>

  325. 

  326. <dl class="py attribute">

  327. <dt class="sig sig-object py" id="reprlib.Repr.maxother">

  328. <span class="sig-prename descclassname"><span class="pre">Repr.</span></span><span class="sig-name descname"><span class="pre">maxother</span></span><a class="headerlink" href="#reprlib.Repr.maxother" title="Link to this definition">¶</a></dt>

  329. <dd><p>This limit is used to control the size of object types for which no specific

  330. formatting method is available on the <a class="reference internal" href="#reprlib.Repr" title="reprlib.Repr"><code class="xref py py-class docutils literal notranslate"><span class="pre">Repr</span></code></a> object. It is applied in a

  331. similar manner as <a class="reference internal" href="#reprlib.Repr.maxstring" title="reprlib.Repr.maxstring"><code class="xref py py-attr docutils literal notranslate"><span class="pre">maxstring</span></code></a>.  The default is <code class="docutils literal notranslate"><span class="pre">20</span></code>.</p>

  332. </dd></dl>

  333. 

  334. <dl class="py attribute">

  335. <dt class="sig sig-object py" id="reprlib.Repr.indent">

  336. <span class="sig-prename descclassname"><span class="pre">Repr.</span></span><span class="sig-name descname"><span class="pre">indent</span></span><a class="headerlink" href="#reprlib.Repr.indent" title="Link to this definition">¶</a></dt>

  337. <dd><p>If this attribute is set to <code class="docutils literal notranslate"><span class="pre">None</span></code> (the default), the output is formatted

  338. with no line breaks or indentation, like the standard <a class="reference internal" href="functions.html#repr" title="repr"><code class="xref py py-func docutils literal notranslate"><span class="pre">repr()</span></code></a>.

  339. For example:</p>

  340. <div class="highlight-pycon notranslate"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">example</span> <span class="o">=</span> <span class="p">[</span>

  341. <span class="gp">... </span>    <span class="mi">1</span><span class="p">,</span> <span class="s1">&#39;spam&#39;</span><span class="p">,</span> <span class="p">{</span><span class="s1">&#39;a&#39;</span><span class="p">:</span> <span class="mi">2</span><span class="p">,</span> <span class="s1">&#39;b&#39;</span><span class="p">:</span> <span class="s1">&#39;spam eggs&#39;</span><span class="p">,</span> <span class="s1">&#39;c&#39;</span><span class="p">:</span> <span class="p">{</span><span class="mi">3</span><span class="p">:</span> <span class="mf">4.5</span><span class="p">,</span> <span class="mi">6</span><span class="p">:</span> <span class="p">[]}},</span> <span class="s1">&#39;ham&#39;</span><span class="p">]</span>

  342. <span class="gp">&gt;&gt;&gt; </span><span class="kn">import</span> <span class="nn">reprlib</span>

  343. <span class="gp">&gt;&gt;&gt; </span><span class="n">aRepr</span> <span class="o">=</span> <span class="n">reprlib</span><span class="o">.</span><span class="n">Repr</span><span class="p">()</span>

  344. <span class="gp">&gt;&gt;&gt; </span><span class="nb">print</span><span class="p">(</span><span class="n">aRepr</span><span class="o">.</span><span class="n">repr</span><span class="p">(</span><span class="n">example</span><span class="p">))</span>

  345. <span class="go">[1, &#39;spam&#39;, {&#39;a&#39;: 2, &#39;b&#39;: &#39;spam eggs&#39;, &#39;c&#39;: {3: 4.5, 6: []}}, &#39;ham&#39;]</span>

  346. </pre></div>

  347. </div>

  348. <p>If <a class="reference internal" href="#reprlib.Repr.indent" title="reprlib.Repr.indent"><code class="xref py py-attr docutils literal notranslate"><span class="pre">indent</span></code></a> is set to a string, each recursion level

  349. is placed on its own line, indented by that string:</p>

  350. <div class="highlight-pycon notranslate"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">aRepr</span><span class="o">.</span><span class="n">indent</span> <span class="o">=</span> <span class="s1">&#39;--&gt;&#39;</span>

  351. <span class="gp">&gt;&gt;&gt; </span><span class="nb">print</span><span class="p">(</span><span class="n">aRepr</span><span class="o">.</span><span class="n">repr</span><span class="p">(</span><span class="n">example</span><span class="p">))</span>

  352. <span class="go">[</span>

  353. <span class="go">--&gt;1,</span>

  354. <span class="go">--&gt;&#39;spam&#39;,</span>

  355. <span class="go">--&gt;{</span>

  356. <span class="go">--&gt;--&gt;&#39;a&#39;: 2,</span>

  357. <span class="go">--&gt;--&gt;&#39;b&#39;: &#39;spam eggs&#39;,</span>

  358. <span class="go">--&gt;--&gt;&#39;c&#39;: {</span>

  359. <span class="go">--&gt;--&gt;--&gt;3: 4.5,</span>

  360. <span class="go">--&gt;--&gt;--&gt;6: [],</span>

  361. <span class="go">--&gt;--&gt;},</span>

  362. <span class="go">--&gt;},</span>

  363. <span class="go">--&gt;&#39;ham&#39;,</span>

  364. <span class="go">]</span>

  365. </pre></div>

  366. </div>

  367. <p>Setting <a class="reference internal" href="#reprlib.Repr.indent" title="reprlib.Repr.indent"><code class="xref py py-attr docutils literal notranslate"><span class="pre">indent</span></code></a> to a positive integer value behaves as if it

  368. was set to a string with that number of spaces:</p>

  369. <div class="highlight-pycon notranslate"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">aRepr</span><span class="o">.</span><span class="n">indent</span> <span class="o">=</span> <span class="mi">4</span>

  370. <span class="gp">&gt;&gt;&gt; </span><span class="nb">print</span><span class="p">(</span><span class="n">aRepr</span><span class="o">.</span><span class="n">repr</span><span class="p">(</span><span class="n">example</span><span class="p">))</span>

  371. <span class="go">[</span>

  372. <span class="go">    1,</span>

  373. <span class="go">    &#39;spam&#39;,</span>

  374. <span class="go">    {</span>

  375. <span class="go">        &#39;a&#39;: 2,</span>

  376. <span class="go">        &#39;b&#39;: &#39;spam eggs&#39;,</span>

  377. <span class="go">        &#39;c&#39;: {</span>

  378. <span class="go">            3: 4.5,</span>

  379. <span class="go">            6: [],</span>

  380. <span class="go">        },</span>

  381. <span class="go">    },</span>

  382. <span class="go">    &#39;ham&#39;,</span>

  383. <span class="go">]</span>

  384. </pre></div>

  385. </div>

  386. <div class="versionadded">

  387. <p><span class="versionmodified added">New in version 3.12.</span></p>

  388. </div>

  389. </dd></dl>

  390. 

  391. <dl class="py method">

  392. <dt class="sig sig-object py" id="reprlib.Repr.repr">

  393. <span class="sig-prename descclassname"><span class="pre">Repr.</span></span><span class="sig-name descname"><span class="pre">repr</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">obj</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#reprlib.Repr.repr" title="Link to this definition">¶</a></dt>

  394. <dd><p>The equivalent to the built-in <a class="reference internal" href="functions.html#repr" title="repr"><code class="xref py py-func docutils literal notranslate"><span class="pre">repr()</span></code></a> that uses the formatting imposed by

  395. the instance.</p>

  396. </dd></dl>

  397. 

  398. <dl class="py method">

  399. <dt class="sig sig-object py" id="reprlib.Repr.repr1">

  400. <span class="sig-prename descclassname"><span class="pre">Repr.</span></span><span class="sig-name descname"><span class="pre">repr1</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">level</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#reprlib.Repr.repr1" title="Link to this definition">¶</a></dt>

  401. <dd><p>Recursive implementation used by <a class="reference internal" href="#reprlib.Repr.repr" title="reprlib.Repr.repr"><code class="xref py py-meth docutils literal notranslate"><span class="pre">repr()</span></code></a>.  This uses the type of <em>obj</em> to

  402. determine which formatting method to call, passing it <em>obj</em> and <em>level</em>.  The

  403. type-specific methods should call <a class="reference internal" href="#reprlib.Repr.repr1" title="reprlib.Repr.repr1"><code class="xref py py-meth docutils literal notranslate"><span class="pre">repr1()</span></code></a> to perform recursive formatting,

  404. with <code class="docutils literal notranslate"><span class="pre">level</span> <span class="pre">-</span> <span class="pre">1</span></code> for the value of <em>level</em> in the recursive  call.</p>

  405. </dd></dl>

  406. 

  407. <dl class="py method">

  408. <dt class="sig sig-object py">

  409. <span class="sig-prename descclassname"><span class="pre">Repr.</span></span><span class="sig-name descname"><span class="pre">repr_TYPE</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">level</span></span></em><span class="sig-paren">)</span></dt>

  410. <dd><p>Formatting methods for specific types are implemented as methods with a name

  411. based on the type name.  In the method name, <strong>TYPE</strong> is replaced by

  412. <code class="docutils literal notranslate"><span class="pre">'_'.join(type(obj).__name__.split())</span></code>. Dispatch to these methods is

  413. handled by <a class="reference internal" href="#reprlib.Repr.repr1" title="reprlib.Repr.repr1"><code class="xref py py-meth docutils literal notranslate"><span class="pre">repr1()</span></code></a>. Type-specific methods which need to recursively

  414. format a value should call <code class="docutils literal notranslate"><span class="pre">self.repr1(subobj,</span> <span class="pre">level</span> <span class="pre">-</span> <span class="pre">1)</span></code>.</p>

  415. </dd></dl>

  416. 

  417. </section>

  418. <section id="subclassing-repr-objects">

  419. <span id="subclassing-reprs"></span><h2>Subclassing Repr Objects<a class="headerlink" href="#subclassing-repr-objects" title="Link to this heading">¶</a></h2>

  420. <p>The use of dynamic dispatching by <a class="reference internal" href="#reprlib.Repr.repr1" title="reprlib.Repr.repr1"><code class="xref py py-meth docutils literal notranslate"><span class="pre">Repr.repr1()</span></code></a> allows subclasses of

  421. <a class="reference internal" href="#reprlib.Repr" title="reprlib.Repr"><code class="xref py py-class docutils literal notranslate"><span class="pre">Repr</span></code></a> to add support for additional built-in object types or to modify

  422. the handling of types already supported. This example shows how special support

  423. for file objects could be added:</p>

  424. <div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="kn">import</span> <span class="nn">reprlib</span>

  425. <span class="kn">import</span> <span class="nn">sys</span>

  426. 

  427. <span class="k">class</span> <span class="nc">MyRepr</span><span class="p">(</span><span class="n">reprlib</span><span class="o">.</span><span class="n">Repr</span><span class="p">):</span>

  428. 

  429.     <span class="k">def</span> <span class="nf">repr_TextIOWrapper</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="n">level</span><span class="p">):</span>

  430.         <span class="k">if</span> <span class="n">obj</span><span class="o">.</span><span class="n">name</span> <span class="ow">in</span> <span class="p">{</span><span class="s1">&#39;&lt;stdin&gt;&#39;</span><span class="p">,</span> <span class="s1">&#39;&lt;stdout&gt;&#39;</span><span class="p">,</span> <span class="s1">&#39;&lt;stderr&gt;&#39;</span><span class="p">}:</span>

  431.             <span class="k">return</span> <span class="n">obj</span><span class="o">.</span><span class="n">name</span>

  432.         <span class="k">return</span> <span class="nb">repr</span><span class="p">(</span><span class="n">obj</span><span class="p">)</span>

  433. 

  434. <span class="n">aRepr</span> <span class="o">=</span> <span class="n">MyRepr</span><span class="p">()</span>

  435. <span class="nb">print</span><span class="p">(</span><span class="n">aRepr</span><span class="o">.</span><span class="n">repr</span><span class="p">(</span><span class="n">sys</span><span class="o">.</span><span class="n">stdin</span><span class="p">))</span>         <span class="c1"># prints &#39;&lt;stdin&gt;&#39;</span>

  436. </pre></div>

  437. </div>

  438. <div class="highlight-none notranslate"><div class="highlight"><pre><span></span>&lt;stdin&gt;

  439. </pre></div>

  440. </div>

  441. </section>

  442. </section>

  443. 

  444. 

  445.             <div class="clearer"></div>

  446.           </div>

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  448.       </div>

  449.       <div class="sphinxsidebar" role="navigation" aria-label="main navigation">

  450.         <div class="sphinxsidebarwrapper">

  451.   <div>

  452.     <h3><a href="../contents.html">Table of Contents</a></h3>

  453.     <ul>

  454. <li><a class="reference internal" href="#"><code class="xref py py-mod docutils literal notranslate"><span class="pre">reprlib</span></code> — Alternate <code class="xref py py-func docutils literal notranslate"><span class="pre">repr()</span></code> implementation</a><ul>

  455. <li><a class="reference internal" href="#repr-objects">Repr Objects</a></li>

  456. <li><a class="reference internal" href="#subclassing-repr-objects">Subclassing Repr Objects</a></li>

  457. </ul>

  458. </li>

  459. </ul>

  460. 

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