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  99. <li><a class="reference internal" href="#madv-constants">MADV_* Constants</a></li>

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

  194. <span id="mmap-memory-mapped-file-support"></span><h1><a class="reference internal" href="#module-mmap" title="mmap: Interface to memory-mapped files for Unix and Windows."><code class="xref py py-mod docutils literal notranslate"><span class="pre">mmap</span></code></a> — Memory-mapped file support<a class="headerlink" href="#module-mmap" title="Link to this heading">¶</a></h1>

  195. <hr class="docutils" />

  196. <div class="availability docutils container">

  197. <p><a class="reference internal" href="intro.html#availability"><span class="std std-ref">Availability</span></a>: not Emscripten, not WASI.</p>

  198. <p>This module does not work or is not available on WebAssembly platforms

  199. <code class="docutils literal notranslate"><span class="pre">wasm32-emscripten</span></code> and <code class="docutils literal notranslate"><span class="pre">wasm32-wasi</span></code>. See

  200. <a class="reference internal" href="intro.html#wasm-availability"><span class="std std-ref">WebAssembly platforms</span></a> for more information.</p>

  201. </div>

  202. <p>Memory-mapped file objects behave like both <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> and like

  203. <a class="reference internal" href="../glossary.html#term-file-object"><span class="xref std std-term">file objects</span></a>.  You can use mmap objects in most places

  204. where <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> are expected; for example, you can use the <a class="reference internal" href="re.html#module-re" title="re: Regular expression operations."><code class="xref py py-mod docutils literal notranslate"><span class="pre">re</span></code></a>

  205. module to search through a memory-mapped file.  You can also change a single

  206. byte by doing <code class="docutils literal notranslate"><span class="pre">obj[index]</span> <span class="pre">=</span> <span class="pre">97</span></code>, or change a subsequence by assigning to a

  207. slice: <code class="docutils literal notranslate"><span class="pre">obj[i1:i2]</span> <span class="pre">=</span> <span class="pre">b'...'</span></code>.  You can also read and write data starting at

  208. the current file position, and <code class="xref py py-meth docutils literal notranslate"><span class="pre">seek()</span></code> through the file to different positions.</p>

  209. <p>A memory-mapped file is created by the <a class="reference internal" href="#mmap.mmap" title="mmap.mmap"><code class="xref py py-class docutils literal notranslate"><span class="pre">mmap</span></code></a> constructor, which is

  210. different on Unix and on Windows.  In either case you must provide a file

  211. descriptor for a file opened for update. If you wish to map an existing Python

  212. file object, use its <a class="reference internal" href="io.html#io.IOBase.fileno" title="io.IOBase.fileno"><code class="xref py py-meth docutils literal notranslate"><span class="pre">fileno()</span></code></a> method to obtain the correct value for the

  213. <em>fileno</em> parameter.  Otherwise, you can open the file using the

  214. <a class="reference internal" href="os.html#os.open" title="os.open"><code class="xref py py-func docutils literal notranslate"><span class="pre">os.open()</span></code></a> function, which returns a file descriptor directly (the file

  215. still needs to be closed when done).</p>

  216. <div class="admonition note">

  217. <p class="admonition-title">Note</p>

  218. <p>If you want to create a memory-mapping for a writable, buffered file, you

  219. should <a class="reference internal" href="io.html#io.IOBase.flush" title="io.IOBase.flush"><code class="xref py py-func docutils literal notranslate"><span class="pre">flush()</span></code></a> the file first.  This is necessary to ensure

  220. that local modifications to the buffers are actually available to the

  221. mapping.</p>

  222. </div>

  223. <p>For both the Unix and Windows versions of the constructor, <em>access</em> may be

  224. specified as an optional keyword parameter. <em>access</em> accepts one of four

  225. values: <code class="xref py py-const docutils literal notranslate"><span class="pre">ACCESS_READ</span></code>, <code class="xref py py-const docutils literal notranslate"><span class="pre">ACCESS_WRITE</span></code>, or <code class="xref py py-const docutils literal notranslate"><span class="pre">ACCESS_COPY</span></code> to

  226. specify read-only, write-through or copy-on-write memory respectively, or

  227. <code class="xref py py-const docutils literal notranslate"><span class="pre">ACCESS_DEFAULT</span></code> to defer to <em>prot</em>.  <em>access</em> can be used on both Unix

  228. and Windows.  If <em>access</em> is not specified, Windows mmap returns a

  229. write-through mapping.  The initial memory values for all three access types

  230. are taken from the specified file.  Assignment to an <code class="xref py py-const docutils literal notranslate"><span class="pre">ACCESS_READ</span></code>

  231. memory map raises 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> exception.  Assignment to an

  232. <code class="xref py py-const docutils literal notranslate"><span class="pre">ACCESS_WRITE</span></code> memory map affects both memory and the underlying file.

  233. Assignment to an <code class="xref py py-const docutils literal notranslate"><span class="pre">ACCESS_COPY</span></code> memory map affects memory but does not

  234. update the underlying file.</p>

  235. <div class="versionchanged">

  236. <p><span class="versionmodified changed">Changed in version 3.7: </span>Added <code class="xref py py-const docutils literal notranslate"><span class="pre">ACCESS_DEFAULT</span></code> constant.</p>

  237. </div>

  238. <p>To map anonymous memory, -1 should be passed as the fileno along with the length.</p>

  239. <dl class="py class">

  240. <dt class="sig sig-object py" id="mmap.mmap">

  241. <em class="property"><span class="pre">class</span><span class="w"> </span></em><span class="sig-prename descclassname"><span class="pre">mmap.</span></span><span class="sig-name descname"><span class="pre">mmap</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">fileno</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">length</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">tagname=None</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">access=ACCESS_DEFAULT</span></span></em><span class="optional">[</span>, <em class="sig-param"><span class="n"><span class="pre">offset</span></span></em><span class="optional">]</span><span class="sig-paren">)</span><a class="headerlink" href="#mmap.mmap" title="Link to this definition">¶</a></dt>

  242. <dd><p><strong>(Windows version)</strong> Maps <em>length</em> bytes from the file specified by the

  243. file handle <em>fileno</em>, and creates a mmap object.  If <em>length</em> is larger

  244. than the current size of the file, the file is extended to contain <em>length</em>

  245. bytes.  If <em>length</em> is <code class="docutils literal notranslate"><span class="pre">0</span></code>, the maximum length of the map is the current

  246. size of the file, except that if the file is empty Windows raises an

  247. exception (you cannot create an empty mapping on Windows).</p>

  248. <p><em>tagname</em>, if specified and not <code class="docutils literal notranslate"><span class="pre">None</span></code>, is a string giving a tag name for

  249. the mapping.  Windows allows you to have many different mappings against

  250. the same file.  If you specify the name of an existing tag, that tag is

  251. opened, otherwise a new tag of this name is created.  If this parameter is

  252. omitted or <code class="docutils literal notranslate"><span class="pre">None</span></code>, the mapping is created without a name.  Avoiding the

  253. use of the <em>tagname</em> parameter will assist in keeping your code portable

  254. between Unix and Windows.</p>

  255. <p><em>offset</em> may be specified as a non-negative integer offset. mmap references

  256. will be relative to the offset from the beginning of the file. <em>offset</em>

  257. defaults to 0.  <em>offset</em> must be a multiple of the <code class="xref py py-const docutils literal notranslate"><span class="pre">ALLOCATIONGRANULARITY</span></code>.</p>

  258. <p class="audit-hook">Raises an <a class="reference internal" href="sys.html#auditing"><span class="std std-ref">auditing event</span></a> <code class="docutils literal notranslate"><span class="pre">mmap.__new__</span></code> with arguments <code class="docutils literal notranslate"><span class="pre">fileno</span></code>, <code class="docutils literal notranslate"><span class="pre">length</span></code>, <code class="docutils literal notranslate"><span class="pre">access</span></code>, <code class="docutils literal notranslate"><span class="pre">offset</span></code>.</p>

  259. </dd></dl>

  260. 

  261. <dl class="py class">

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

  263. <em class="property"><span class="pre">class</span><span class="w"> </span></em><span class="sig-prename descclassname"><span class="pre">mmap.</span></span><span class="sig-name descname"><span class="pre">mmap</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">fileno</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">length</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">flags=MAP_SHARED</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">prot=PROT_WRITE|PROT_READ</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">access=ACCESS_DEFAULT</span></span></em><span class="optional">[</span>, <em class="sig-param"><span class="n"><span class="pre">offset</span></span></em><span class="optional">]</span><span class="sig-paren">)</span></dt>

  264. <dd><p><strong>(Unix version)</strong> Maps <em>length</em> bytes from the file specified by the file

  265. descriptor <em>fileno</em>, and returns a mmap object.  If <em>length</em> is <code class="docutils literal notranslate"><span class="pre">0</span></code>, the

  266. maximum length of the map will be the current size of the file when

  267. <a class="reference internal" href="#mmap.mmap" title="mmap.mmap"><code class="xref py py-class docutils literal notranslate"><span class="pre">mmap</span></code></a> is called.</p>

  268. <p><em>flags</em> specifies the nature of the mapping. <a class="reference internal" href="#mmap.MAP_PRIVATE" title="mmap.MAP_PRIVATE"><code class="xref py py-const docutils literal notranslate"><span class="pre">MAP_PRIVATE</span></code></a> creates a

  269. private copy-on-write mapping, so changes to the contents of the mmap

  270. object will be private to this process, and <a class="reference internal" href="#mmap.MAP_SHARED" title="mmap.MAP_SHARED"><code class="xref py py-const docutils literal notranslate"><span class="pre">MAP_SHARED</span></code></a> creates a

  271. mapping that’s shared with all other processes mapping the same areas of

  272. the file.  The default value is <a class="reference internal" href="#mmap.MAP_SHARED" title="mmap.MAP_SHARED"><code class="xref py py-const docutils literal notranslate"><span class="pre">MAP_SHARED</span></code></a>. Some systems have

  273. additional possible flags with the full list specified in

  274. <a class="reference internal" href="#map-constants"><span class="std std-ref">MAP_* constants</span></a>.</p>

  275. <p><em>prot</em>, if specified, gives the desired memory protection; the two most

  276. useful values are <code class="xref py py-const docutils literal notranslate"><span class="pre">PROT_READ</span></code> and <code class="xref py py-const docutils literal notranslate"><span class="pre">PROT_WRITE</span></code>, to specify

  277. that the pages may be read or written.  <em>prot</em> defaults to

  278. <code class="xref py py-const docutils literal notranslate"><span class="pre">PROT_READ</span> <span class="pre">|</span> <span class="pre">PROT_WRITE</span></code>.</p>

  279. <p><em>access</em> may be specified in lieu of <em>flags</em> and <em>prot</em> as an optional

  280. keyword parameter.  It is an error to specify both <em>flags</em>, <em>prot</em> and

  281. <em>access</em>.  See the description of <em>access</em> above for information on how to

  282. use this parameter.</p>

  283. <p><em>offset</em> may be specified as a non-negative integer offset. mmap references

  284. will be relative to the offset from the beginning of the file. <em>offset</em>

  285. defaults to 0. <em>offset</em> must be a multiple of <code class="xref py py-const docutils literal notranslate"><span class="pre">ALLOCATIONGRANULARITY</span></code>

  286. which is equal to <code class="xref py py-const docutils literal notranslate"><span class="pre">PAGESIZE</span></code> on Unix systems.</p>

  287. <p>To ensure validity of the created memory mapping the file specified

  288. by the descriptor <em>fileno</em> is internally automatically synchronized

  289. with the physical backing store on macOS.</p>

  290. <p>This example shows a simple way of using <a class="reference internal" href="#mmap.mmap" title="mmap.mmap"><code class="xref py py-class docutils literal notranslate"><span class="pre">mmap</span></code></a>:</p>

  291. <div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="kn">import</span> <span class="nn">mmap</span>

  292. 

  293. <span class="c1"># write a simple example file</span>

  294. <span class="k">with</span> <span class="nb">open</span><span class="p">(</span><span class="s2">&quot;hello.txt&quot;</span><span class="p">,</span> <span class="s2">&quot;wb&quot;</span><span class="p">)</span> <span class="k">as</span> <span class="n">f</span><span class="p">:</span>

  295.     <span class="n">f</span><span class="o">.</span><span class="n">write</span><span class="p">(</span><span class="sa">b</span><span class="s2">&quot;Hello Python!</span><span class="se">\n</span><span class="s2">&quot;</span><span class="p">)</span>

  296. 

  297. <span class="k">with</span> <span class="nb">open</span><span class="p">(</span><span class="s2">&quot;hello.txt&quot;</span><span class="p">,</span> <span class="s2">&quot;r+b&quot;</span><span class="p">)</span> <span class="k">as</span> <span class="n">f</span><span class="p">:</span>

  298.     <span class="c1"># memory-map the file, size 0 means whole file</span>

  299.     <span class="n">mm</span> <span class="o">=</span> <span class="n">mmap</span><span class="o">.</span><span class="n">mmap</span><span class="p">(</span><span class="n">f</span><span class="o">.</span><span class="n">fileno</span><span class="p">(),</span> <span class="mi">0</span><span class="p">)</span>

  300.     <span class="c1"># read content via standard file methods</span>

  301.     <span class="nb">print</span><span class="p">(</span><span class="n">mm</span><span class="o">.</span><span class="n">readline</span><span class="p">())</span>  <span class="c1"># prints b&quot;Hello Python!\n&quot;</span>

  302.     <span class="c1"># read content via slice notation</span>

  303.     <span class="nb">print</span><span class="p">(</span><span class="n">mm</span><span class="p">[:</span><span class="mi">5</span><span class="p">])</span>  <span class="c1"># prints b&quot;Hello&quot;</span>

  304.     <span class="c1"># update content using slice notation;</span>

  305.     <span class="c1"># note that new content must have same size</span>

  306.     <span class="n">mm</span><span class="p">[</span><span class="mi">6</span><span class="p">:]</span> <span class="o">=</span> <span class="sa">b</span><span class="s2">&quot; world!</span><span class="se">\n</span><span class="s2">&quot;</span>

  307.     <span class="c1"># ... and read again using standard file methods</span>

  308.     <span class="n">mm</span><span class="o">.</span><span class="n">seek</span><span class="p">(</span><span class="mi">0</span><span class="p">)</span>

  309.     <span class="nb">print</span><span class="p">(</span><span class="n">mm</span><span class="o">.</span><span class="n">readline</span><span class="p">())</span>  <span class="c1"># prints b&quot;Hello  world!\n&quot;</span>

  310.     <span class="c1"># close the map</span>

  311.     <span class="n">mm</span><span class="o">.</span><span class="n">close</span><span class="p">()</span>

  312. </pre></div>

  313. </div>

  314. <p><a class="reference internal" href="#mmap.mmap" title="mmap.mmap"><code class="xref py py-class docutils literal notranslate"><span class="pre">mmap</span></code></a> can also be used as a context manager in a <a class="reference internal" href="../reference/compound_stmts.html#with"><code class="xref std std-keyword docutils literal notranslate"><span class="pre">with</span></code></a>

  315. statement:</p>

  316. <div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="kn">import</span> <span class="nn">mmap</span>

  317. 

  318. <span class="k">with</span> <span class="n">mmap</span><span class="o">.</span><span class="n">mmap</span><span class="p">(</span><span class="o">-</span><span class="mi">1</span><span class="p">,</span> <span class="mi">13</span><span class="p">)</span> <span class="k">as</span> <span class="n">mm</span><span class="p">:</span>

  319.     <span class="n">mm</span><span class="o">.</span><span class="n">write</span><span class="p">(</span><span class="sa">b</span><span class="s2">&quot;Hello world!&quot;</span><span class="p">)</span>

  320. </pre></div>

  321. </div>

  322. <div class="versionadded">

  323. <p><span class="versionmodified added">New in version 3.2: </span>Context manager support.</p>

  324. </div>

  325. <p>The next example demonstrates how to create an anonymous map and exchange

  326. data between the parent and child processes:</p>

  327. <div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="kn">import</span> <span class="nn">mmap</span>

  328. <span class="kn">import</span> <span class="nn">os</span>

  329. 

  330. <span class="n">mm</span> <span class="o">=</span> <span class="n">mmap</span><span class="o">.</span><span class="n">mmap</span><span class="p">(</span><span class="o">-</span><span class="mi">1</span><span class="p">,</span> <span class="mi">13</span><span class="p">)</span>

  331. <span class="n">mm</span><span class="o">.</span><span class="n">write</span><span class="p">(</span><span class="sa">b</span><span class="s2">&quot;Hello world!&quot;</span><span class="p">)</span>

  332. 

  333. <span class="n">pid</span> <span class="o">=</span> <span class="n">os</span><span class="o">.</span><span class="n">fork</span><span class="p">()</span>

  334. 

  335. <span class="k">if</span> <span class="n">pid</span> <span class="o">==</span> <span class="mi">0</span><span class="p">:</span>  <span class="c1"># In a child process</span>

  336.     <span class="n">mm</span><span class="o">.</span><span class="n">seek</span><span class="p">(</span><span class="mi">0</span><span class="p">)</span>

  337.     <span class="nb">print</span><span class="p">(</span><span class="n">mm</span><span class="o">.</span><span class="n">readline</span><span class="p">())</span>

  338. 

  339.     <span class="n">mm</span><span class="o">.</span><span class="n">close</span><span class="p">()</span>

  340. </pre></div>

  341. </div>

  342. <p class="audit-hook">Raises an <a class="reference internal" href="sys.html#auditing"><span class="std std-ref">auditing event</span></a> <code class="docutils literal notranslate"><span class="pre">mmap.__new__</span></code> with arguments <code class="docutils literal notranslate"><span class="pre">fileno</span></code>, <code class="docutils literal notranslate"><span class="pre">length</span></code>, <code class="docutils literal notranslate"><span class="pre">access</span></code>, <code class="docutils literal notranslate"><span class="pre">offset</span></code>.</p>

  343. <p>Memory-mapped file objects support the following methods:</p>

  344. <dl class="py method">

  345. <dt class="sig sig-object py" id="mmap.mmap.close">

  346. <span class="sig-name descname"><span class="pre">close</span></span><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#mmap.mmap.close" title="Link to this definition">¶</a></dt>

  347. <dd><p>Closes the mmap. Subsequent calls to other methods of the object will

  348. result in a ValueError exception being raised. This will not close

  349. the open file.</p>

  350. </dd></dl>

  351. 

  352. <dl class="py attribute">

  353. <dt class="sig sig-object py" id="mmap.mmap.closed">

  354. <span class="sig-name descname"><span class="pre">closed</span></span><a class="headerlink" href="#mmap.mmap.closed" title="Link to this definition">¶</a></dt>

  355. <dd><p><code class="docutils literal notranslate"><span class="pre">True</span></code> if the file is closed.</p>

  356. <div class="versionadded">

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

  358. </div>

  359. </dd></dl>

  360. 

  361. <dl class="py method">

  362. <dt class="sig sig-object py" id="mmap.mmap.find">

  363. <span class="sig-name descname"><span class="pre">find</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">sub</span></span></em><span class="optional">[</span>, <em class="sig-param"><span class="n"><span class="pre">start</span></span></em><span class="optional">[</span>, <em class="sig-param"><span class="n"><span class="pre">end</span></span></em><span class="optional">]</span><span class="optional">]</span><span class="sig-paren">)</span><a class="headerlink" href="#mmap.mmap.find" title="Link to this definition">¶</a></dt>

  364. <dd><p>Returns the lowest index in the object where the subsequence <em>sub</em> is

  365. found, such that <em>sub</em> is contained in the range [<em>start</em>, <em>end</em>].

  366. Optional arguments <em>start</em> and <em>end</em> are interpreted as in slice notation.

  367. Returns <code class="docutils literal notranslate"><span class="pre">-1</span></code> on failure.</p>

  368. <div class="versionchanged">

  369. <p><span class="versionmodified changed">Changed in version 3.5: </span>Writable <a class="reference internal" href="../glossary.html#term-bytes-like-object"><span class="xref std std-term">bytes-like object</span></a> is now accepted.</p>

  370. </div>

  371. </dd></dl>

  372. 

  373. <dl class="py method">

  374. <dt class="sig sig-object py" id="mmap.mmap.flush">

  375. <span class="sig-name descname"><span class="pre">flush</span></span><span class="sig-paren">(</span><span class="optional">[</span><em class="sig-param"><span class="n"><span class="pre">offset</span></span></em><span class="optional">[</span>, <em class="sig-param"><span class="n"><span class="pre">size</span></span></em><span class="optional">]</span><span class="optional">]</span><span class="sig-paren">)</span><a class="headerlink" href="#mmap.mmap.flush" title="Link to this definition">¶</a></dt>

  376. <dd><p>Flushes changes made to the in-memory copy of a file back to disk. Without

  377. use of this call there is no guarantee that changes are written back before

  378. the object is destroyed.  If <em>offset</em> and <em>size</em> are specified, only

  379. changes to the given range of bytes will be flushed to disk; otherwise, the

  380. whole extent of the mapping is flushed.  <em>offset</em> must be a multiple of the

  381. <code class="xref py py-const docutils literal notranslate"><span class="pre">PAGESIZE</span></code> or <code class="xref py py-const docutils literal notranslate"><span class="pre">ALLOCATIONGRANULARITY</span></code>.</p>

  382. <p><code class="docutils literal notranslate"><span class="pre">None</span></code> is returned to indicate success.  An exception is raised when the

  383. call failed.</p>

  384. <div class="versionchanged">

  385. <p><span class="versionmodified changed">Changed in version 3.8: </span>Previously, a nonzero value was returned on success; zero was returned

  386. on error under Windows.  A zero value was returned on success; an

  387. exception was raised on error under Unix.</p>

  388. </div>

  389. </dd></dl>

  390. 

  391. <dl class="py method">

  392. <dt class="sig sig-object py" id="mmap.mmap.madvise">

  393. <span class="sig-name descname"><span class="pre">madvise</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">option</span></span></em><span class="optional">[</span>, <em class="sig-param"><span class="n"><span class="pre">start</span></span></em><span class="optional">[</span>, <em class="sig-param"><span class="n"><span class="pre">length</span></span></em><span class="optional">]</span><span class="optional">]</span><span class="sig-paren">)</span><a class="headerlink" href="#mmap.mmap.madvise" title="Link to this definition">¶</a></dt>

  394. <dd><p>Send advice <em>option</em> to the kernel about the memory region beginning at

  395. <em>start</em> and extending <em>length</em> bytes.  <em>option</em> must be one of the

  396. <a class="reference internal" href="#madvise-constants"><span class="std std-ref">MADV_* constants</span></a> available on the system.  If

  397. <em>start</em> and <em>length</em> are omitted, the entire mapping is spanned.  On

  398. some systems (including Linux), <em>start</em> must be a multiple of the

  399. <code class="xref py py-const docutils literal notranslate"><span class="pre">PAGESIZE</span></code>.</p>

  400. <p>Availability: Systems with the <code class="docutils literal notranslate"><span class="pre">madvise()</span></code> system call.</p>

  401. <div class="versionadded">

  402. <p><span class="versionmodified added">New in version 3.8.</span></p>

  403. </div>

  404. </dd></dl>

  405. 

  406. <dl class="py method">

  407. <dt class="sig sig-object py" id="mmap.mmap.move">

  408. <span class="sig-name descname"><span class="pre">move</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">dest</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">src</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">count</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#mmap.mmap.move" title="Link to this definition">¶</a></dt>

  409. <dd><p>Copy the <em>count</em> bytes starting at offset <em>src</em> to the destination index

  410. <em>dest</em>.  If the mmap was created with <code class="xref py py-const docutils literal notranslate"><span class="pre">ACCESS_READ</span></code>, then calls to

  411. move will 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> exception.</p>

  412. </dd></dl>

  413. 

  414. <dl class="py method">

  415. <dt class="sig sig-object py" id="mmap.mmap.read">

  416. <span class="sig-name descname"><span class="pre">read</span></span><span class="sig-paren">(</span><span class="optional">[</span><em class="sig-param"><span class="n"><span class="pre">n</span></span></em><span class="optional">]</span><span class="sig-paren">)</span><a class="headerlink" href="#mmap.mmap.read" title="Link to this definition">¶</a></dt>

  417. <dd><p>Return 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> containing up to <em>n</em> bytes starting from the

  418. current file position. If the argument is omitted, <code class="docutils literal notranslate"><span class="pre">None</span></code> or negative,

  419. return all bytes from the current file position to the end of the

  420. mapping. The file position is updated to point after the bytes that were

  421. returned.</p>

  422. <div class="versionchanged">

  423. <p><span class="versionmodified changed">Changed in version 3.3: </span>Argument can be omitted or <code class="docutils literal notranslate"><span class="pre">None</span></code>.</p>

  424. </div>

  425. </dd></dl>

  426. 

  427. <dl class="py method">

  428. <dt class="sig sig-object py" id="mmap.mmap.read_byte">

  429. <span class="sig-name descname"><span class="pre">read_byte</span></span><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#mmap.mmap.read_byte" title="Link to this definition">¶</a></dt>

  430. <dd><p>Returns a byte at the current file position as an integer, and advances

  431. the file position by 1.</p>

  432. </dd></dl>

  433. 

  434. <dl class="py method">

  435. <dt class="sig sig-object py" id="mmap.mmap.readline">

  436. <span class="sig-name descname"><span class="pre">readline</span></span><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#mmap.mmap.readline" title="Link to this definition">¶</a></dt>

  437. <dd><p>Returns a single line, starting at the current file position and up to the

  438. next newline. The file position is updated to point after the bytes that were

  439. returned.</p>

  440. </dd></dl>

  441. 

  442. <dl class="py method">

  443. <dt class="sig sig-object py" id="mmap.mmap.resize">

  444. <span class="sig-name descname"><span class="pre">resize</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">newsize</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#mmap.mmap.resize" title="Link to this definition">¶</a></dt>

  445. <dd><p>Resizes the map and the underlying file, if any. If the mmap was created

  446. with <code class="xref py py-const docutils literal notranslate"><span class="pre">ACCESS_READ</span></code> or <code class="xref py py-const docutils literal notranslate"><span class="pre">ACCESS_COPY</span></code>, resizing the map will

  447. 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> exception.</p>

  448. <p><strong>On Windows</strong>: Resizing the map will raise an <a class="reference internal" href="exceptions.html#OSError" title="OSError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">OSError</span></code></a> if there are other

  449. maps against the same named file. Resizing an anonymous map (ie against the

  450. pagefile) will silently create a new map with the original data copied over

  451. up to the length of the new size.</p>

  452. <div class="versionchanged">

  453. <p><span class="versionmodified changed">Changed in version 3.11: </span>Correctly fails if attempting to resize when another map is held

  454. Allows resize against an anonymous map on Windows</p>

  455. </div>

  456. </dd></dl>

  457. 

  458. <dl class="py method">

  459. <dt class="sig sig-object py" id="mmap.mmap.rfind">

  460. <span class="sig-name descname"><span class="pre">rfind</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">sub</span></span></em><span class="optional">[</span>, <em class="sig-param"><span class="n"><span class="pre">start</span></span></em><span class="optional">[</span>, <em class="sig-param"><span class="n"><span class="pre">end</span></span></em><span class="optional">]</span><span class="optional">]</span><span class="sig-paren">)</span><a class="headerlink" href="#mmap.mmap.rfind" title="Link to this definition">¶</a></dt>

  461. <dd><p>Returns the highest index in the object where the subsequence <em>sub</em> is

  462. found, such that <em>sub</em> is contained in the range [<em>start</em>, <em>end</em>].

  463. Optional arguments <em>start</em> and <em>end</em> are interpreted as in slice notation.

  464. Returns <code class="docutils literal notranslate"><span class="pre">-1</span></code> on failure.</p>

  465. <div class="versionchanged">

  466. <p><span class="versionmodified changed">Changed in version 3.5: </span>Writable <a class="reference internal" href="../glossary.html#term-bytes-like-object"><span class="xref std std-term">bytes-like object</span></a> is now accepted.</p>

  467. </div>

  468. </dd></dl>

  469. 

  470. <dl class="py method">

  471. <dt class="sig sig-object py" id="mmap.mmap.seek">

  472. <span class="sig-name descname"><span class="pre">seek</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">pos</span></span></em><span class="optional">[</span>, <em class="sig-param"><span class="n"><span class="pre">whence</span></span></em><span class="optional">]</span><span class="sig-paren">)</span><a class="headerlink" href="#mmap.mmap.seek" title="Link to this definition">¶</a></dt>

  473. <dd><p>Set the file’s current position.  <em>whence</em> argument is optional and

  474. defaults to <code class="docutils literal notranslate"><span class="pre">os.SEEK_SET</span></code> or <code class="docutils literal notranslate"><span class="pre">0</span></code> (absolute file positioning); other

  475. values are <code class="docutils literal notranslate"><span class="pre">os.SEEK_CUR</span></code> or <code class="docutils literal notranslate"><span class="pre">1</span></code> (seek relative to the current

  476. position) and <code class="docutils literal notranslate"><span class="pre">os.SEEK_END</span></code> or <code class="docutils literal notranslate"><span class="pre">2</span></code> (seek relative to the file’s end).</p>

  477. </dd></dl>

  478. 

  479. <dl class="py method">

  480. <dt class="sig sig-object py" id="mmap.mmap.size">

  481. <span class="sig-name descname"><span class="pre">size</span></span><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#mmap.mmap.size" title="Link to this definition">¶</a></dt>

  482. <dd><p>Return the length of the file, which can be larger than the size of the

  483. memory-mapped area.</p>

  484. </dd></dl>

  485. 

  486. <dl class="py method">

  487. <dt class="sig sig-object py" id="mmap.mmap.tell">

  488. <span class="sig-name descname"><span class="pre">tell</span></span><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#mmap.mmap.tell" title="Link to this definition">¶</a></dt>

  489. <dd><p>Returns the current position of the file pointer.</p>

  490. </dd></dl>

  491. 

  492. <dl class="py method">

  493. <dt class="sig sig-object py" id="mmap.mmap.write">

  494. <span class="sig-name descname"><span class="pre">write</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">bytes</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#mmap.mmap.write" title="Link to this definition">¶</a></dt>

  495. <dd><p>Write the bytes in <em>bytes</em> into memory at the current position of the

  496. file pointer and return the number of bytes written (never less than

  497. <code class="docutils literal notranslate"><span class="pre">len(bytes)</span></code>, since if the write fails, 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> will be

  498. raised).  The file position is updated to point after the bytes that

  499. were written.  If the mmap was created with <code class="xref py py-const docutils literal notranslate"><span class="pre">ACCESS_READ</span></code>, then

  500. writing to it will 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> exception.</p>

  501. <div class="versionchanged">

  502. <p><span class="versionmodified changed">Changed in version 3.5: </span>Writable <a class="reference internal" href="../glossary.html#term-bytes-like-object"><span class="xref std std-term">bytes-like object</span></a> is now accepted.</p>

  503. </div>

  504. <div class="versionchanged">

  505. <p><span class="versionmodified changed">Changed in version 3.6: </span>The number of bytes written is now returned.</p>

  506. </div>

  507. </dd></dl>

  508. 

  509. <dl class="py method">

  510. <dt class="sig sig-object py" id="mmap.mmap.write_byte">

  511. <span class="sig-name descname"><span class="pre">write_byte</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">byte</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#mmap.mmap.write_byte" title="Link to this definition">¶</a></dt>

  512. <dd><p>Write the integer <em>byte</em> into memory at the current

  513. position of the file pointer; the file position is advanced by <code class="docutils literal notranslate"><span class="pre">1</span></code>. If

  514. the mmap was created with <code class="xref py py-const docutils literal notranslate"><span class="pre">ACCESS_READ</span></code>, then writing to it will

  515. 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> exception.</p>

  516. </dd></dl>

  517. 

  518. </dd></dl>

  519. 

  520. <section id="madv-constants">

  521. <span id="madvise-constants"></span><h2>MADV_* Constants<a class="headerlink" href="#madv-constants" title="Link to this heading">¶</a></h2>

  522. <dl class="py data">

  523. <dt class="sig sig-object py" id="mmap.MADV_NORMAL">

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

  525. <dt class="sig sig-object py" id="mmap.MADV_RANDOM">

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

  527. <dt class="sig sig-object py" id="mmap.MADV_SEQUENTIAL">

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

  529. <dt class="sig sig-object py" id="mmap.MADV_WILLNEED">

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

  531. <dt class="sig sig-object py" id="mmap.MADV_DONTNEED">

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

  533. <dt class="sig sig-object py" id="mmap.MADV_REMOVE">

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

  535. <dt class="sig sig-object py" id="mmap.MADV_DONTFORK">

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

  537. <dt class="sig sig-object py" id="mmap.MADV_DOFORK">

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

  539. <dt class="sig sig-object py" id="mmap.MADV_HWPOISON">

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

  541. <dt class="sig sig-object py" id="mmap.MADV_MERGEABLE">

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

  543. <dt class="sig sig-object py" id="mmap.MADV_UNMERGEABLE">

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

  545. <dt class="sig sig-object py" id="mmap.MADV_SOFT_OFFLINE">

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

  547. <dt class="sig sig-object py" id="mmap.MADV_HUGEPAGE">

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

  549. <dt class="sig sig-object py" id="mmap.MADV_NOHUGEPAGE">

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

  551. <dt class="sig sig-object py" id="mmap.MADV_DONTDUMP">

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

  553. <dt class="sig sig-object py" id="mmap.MADV_DODUMP">

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

  555. <dt class="sig sig-object py" id="mmap.MADV_FREE">

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

  557. <dt class="sig sig-object py" id="mmap.MADV_NOSYNC">

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

  559. <dt class="sig sig-object py" id="mmap.MADV_AUTOSYNC">

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

  561. <dt class="sig sig-object py" id="mmap.MADV_NOCORE">

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

  563. <dt class="sig sig-object py" id="mmap.MADV_CORE">

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

  565. <dt class="sig sig-object py" id="mmap.MADV_PROTECT">

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

  567. <dt class="sig sig-object py" id="mmap.MADV_FREE_REUSABLE">

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

  569. <dt class="sig sig-object py" id="mmap.MADV_FREE_REUSE">

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

  571. <dd><p>These options can be passed to <a class="reference internal" href="#mmap.mmap.madvise" title="mmap.mmap.madvise"><code class="xref py py-meth docutils literal notranslate"><span class="pre">mmap.madvise()</span></code></a>.  Not every option will

  572. be present on every system.</p>

  573. <p>Availability: Systems with the madvise() system call.</p>

  574. <div class="versionadded">

  575. <p><span class="versionmodified added">New in version 3.8.</span></p>

  576. </div>

  577. </dd></dl>

  578. 

  579. </section>

  580. <section id="map-constants">

  581. <span id="id1"></span><h2>MAP_* Constants<a class="headerlink" href="#map-constants" title="Link to this heading">¶</a></h2>

  582. <dl class="py data">

  583. <dt class="sig sig-object py" id="mmap.MAP_SHARED">

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

  585. <dt class="sig sig-object py" id="mmap.MAP_PRIVATE">

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

  587. <dt class="sig sig-object py" id="mmap.MAP_DENYWRITE">

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

  589. <dt class="sig sig-object py" id="mmap.MAP_EXECUTABLE">

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

  591. <dt class="sig sig-object py" id="mmap.MAP_ANON">

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

  593. <dt class="sig sig-object py" id="mmap.MAP_ANONYMOUS">

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

  595. <dt class="sig sig-object py" id="mmap.MAP_POPULATE">

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

  597. <dt class="sig sig-object py" id="mmap.MAP_STACK">

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

  599. <dt class="sig sig-object py" id="mmap.MAP_ALIGNED_SUPER">

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

  601. <dt class="sig sig-object py" id="mmap.MAP_CONCEAL">

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

  603. <dd><p>These are the various flags that can be passed to <a class="reference internal" href="#mmap.mmap" title="mmap.mmap"><code class="xref py py-meth docutils literal notranslate"><span class="pre">mmap.mmap()</span></code></a>.  <a class="reference internal" href="#mmap.MAP_ALIGNED_SUPER" title="mmap.MAP_ALIGNED_SUPER"><code class="xref py py-data docutils literal notranslate"><span class="pre">MAP_ALIGNED_SUPER</span></code></a>

  604. is only available at FreeBSD and <a class="reference internal" href="#mmap.MAP_CONCEAL" title="mmap.MAP_CONCEAL"><code class="xref py py-data docutils literal notranslate"><span class="pre">MAP_CONCEAL</span></code></a> is only available at OpenBSD.  Note

  605. that some options might not be present on some systems.</p>

  606. <div class="versionchanged">

  607. <p><span class="versionmodified changed">Changed in version 3.10: </span>Added <a class="reference internal" href="#mmap.MAP_POPULATE" title="mmap.MAP_POPULATE"><code class="xref py py-data docutils literal notranslate"><span class="pre">MAP_POPULATE</span></code></a> constant.</p>

  608. </div>

  609. <div class="versionadded">

  610. <p><span class="versionmodified added">New in version 3.11: </span>Added <a class="reference internal" href="#mmap.MAP_STACK" title="mmap.MAP_STACK"><code class="xref py py-data docutils literal notranslate"><span class="pre">MAP_STACK</span></code></a> constant.</p>

  611. </div>

  612. <div class="versionadded">

  613. <p><span class="versionmodified added">New in version 3.12: </span>Added <a class="reference internal" href="#mmap.MAP_ALIGNED_SUPER" title="mmap.MAP_ALIGNED_SUPER"><code class="xref py py-data docutils literal notranslate"><span class="pre">MAP_ALIGNED_SUPER</span></code></a> constant.

  614. Added <a class="reference internal" href="#mmap.MAP_CONCEAL" title="mmap.MAP_CONCEAL"><code class="xref py py-data docutils literal notranslate"><span class="pre">MAP_CONCEAL</span></code></a> constant.</p>

  615. </div>

  616. </dd></dl>

  617. 

  618. </section>

  619. </section>

  620. 

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  632. <li><a class="reference internal" href="#madv-constants">MADV_* Constants</a></li>

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