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<span id="array-efficient-arrays-of-numeric-values"></span><h1><a class="reference internal" href="#module-array" title="array: Space efficient arrays of uniformly typed numeric values."><code class="xref py py-mod docutils literal notranslate"><span class="pre">array</span></code></a> — Efficient arrays of numeric values<a class="headerlink" href="#module-array" title="Permalink to this headline">¶</a></h1>
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<hr class="docutils" id="index-0" />
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<p>This module defines an object type which can compactly represent an array of
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basic values: characters, integers, floating point numbers. Arrays are sequence
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types and behave very much like lists, except that the type of objects stored in
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them is constrained. The type is specified at object creation time by using a
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<em class="dfn">type code</em>, which is a single character. The following type codes are
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defined:</p>
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</colgroup>
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<thead>
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<tr class="row-odd"><th class="head"><p>Type code</p></th>
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<th class="head"><p>C Type</p></th>
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<th class="head"><p>Python Type</p></th>
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<th class="head"><p>Minimum size in bytes</p></th>
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<th class="head"><p>Notes</p></th>
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</tr>
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</thead>
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<tbody>
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<tr class="row-even"><td><p><code class="docutils literal notranslate"><span class="pre">'b'</span></code></p></td>
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<td><p>signed char</p></td>
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<td><p>int</p></td>
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<td><p>1</p></td>
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<td></td>
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</tr>
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<tr class="row-odd"><td><p><code class="docutils literal notranslate"><span class="pre">'B'</span></code></p></td>
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<td><p>unsigned char</p></td>
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<td><p>int</p></td>
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<td><p>1</p></td>
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<td></td>
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</tr>
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<tr class="row-even"><td><p><code class="docutils literal notranslate"><span class="pre">'u'</span></code></p></td>
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<td><p>Py_UNICODE</p></td>
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<td><p>Unicode character</p></td>
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<td><p>2</p></td>
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<td><p>(1)</p></td>
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</tr>
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<tr class="row-odd"><td><p><code class="docutils literal notranslate"><span class="pre">'h'</span></code></p></td>
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<td><p>signed short</p></td>
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<td><p>int</p></td>
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<td><p>2</p></td>
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<td></td>
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</tr>
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<tr class="row-even"><td><p><code class="docutils literal notranslate"><span class="pre">'H'</span></code></p></td>
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<td><p>unsigned short</p></td>
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<td><p>int</p></td>
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<td><p>2</p></td>
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<td></td>
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</tr>
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<tr class="row-odd"><td><p><code class="docutils literal notranslate"><span class="pre">'i'</span></code></p></td>
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<td><p>signed int</p></td>
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<td><p>int</p></td>
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<td><p>2</p></td>
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<td></td>
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</tr>
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<tr class="row-even"><td><p><code class="docutils literal notranslate"><span class="pre">'I'</span></code></p></td>
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<td><p>unsigned int</p></td>
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<td><p>int</p></td>
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<td><p>2</p></td>
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<td></td>
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</tr>
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<tr class="row-odd"><td><p><code class="docutils literal notranslate"><span class="pre">'l'</span></code></p></td>
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<td><p>signed long</p></td>
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<td><p>int</p></td>
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<td><p>4</p></td>
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<td></td>
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</tr>
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<tr class="row-even"><td><p><code class="docutils literal notranslate"><span class="pre">'L'</span></code></p></td>
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<td><p>unsigned long</p></td>
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<td><p>int</p></td>
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<td><p>4</p></td>
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<td></td>
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</tr>
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<tr class="row-odd"><td><p><code class="docutils literal notranslate"><span class="pre">'q'</span></code></p></td>
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<td><p>signed long long</p></td>
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<td><p>int</p></td>
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<td><p>8</p></td>
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<td><p>(2)</p></td>
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</tr>
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<tr class="row-even"><td><p><code class="docutils literal notranslate"><span class="pre">'Q'</span></code></p></td>
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<td><p>unsigned long long</p></td>
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<td><p>int</p></td>
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<td><p>8</p></td>
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<td><p>(2)</p></td>
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</tr>
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<tr class="row-odd"><td><p><code class="docutils literal notranslate"><span class="pre">'f'</span></code></p></td>
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<td><p>float</p></td>
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<td><p>float</p></td>
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<td><p>4</p></td>
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<td></td>
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</tr>
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<tr class="row-even"><td><p><code class="docutils literal notranslate"><span class="pre">'d'</span></code></p></td>
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<td><p>double</p></td>
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<td><p>float</p></td>
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<td><p>8</p></td>
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<td></td>
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</tr>
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</tbody>
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</table>
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<p>Notes:</p>
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<ol class="arabic">
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<li><p>The <code class="docutils literal notranslate"><span class="pre">'u'</span></code> type code corresponds to Python’s obsolete unicode character
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(<a class="reference internal" href="../c-api/unicode.html#c.Py_UNICODE" title="Py_UNICODE"><code class="xref c c-type docutils literal notranslate"><span class="pre">Py_UNICODE</span></code></a> which is <code class="xref c c-type docutils literal notranslate"><span class="pre">wchar_t</span></code>). Depending on the
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platform, it can be 16 bits or 32 bits.</p>
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<p><code class="docutils literal notranslate"><span class="pre">'u'</span></code> will be removed together with the rest of the <a class="reference internal" href="../c-api/unicode.html#c.Py_UNICODE" title="Py_UNICODE"><code class="xref c c-type docutils literal notranslate"><span class="pre">Py_UNICODE</span></code></a>
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API.</p>
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<div class="deprecated">
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<p><span class="versionmodified">Deprecated since version 3.3, will be removed in version 4.0.</span></p>
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</div>
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</li>
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<li><p>The <code class="docutils literal notranslate"><span class="pre">'q'</span></code> and <code class="docutils literal notranslate"><span class="pre">'Q'</span></code> type codes are available only if
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the platform C compiler used to build Python supports C <code class="xref c c-type docutils literal notranslate"><span class="pre">long</span> <span class="pre">long</span></code>,
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or, on Windows, <code class="xref c c-type docutils literal notranslate"><span class="pre">__int64</span></code>.</p>
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<div class="versionadded">
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<p><span class="versionmodified added">New in version 3.3.</span></p>
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</div>
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</li>
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</ol>
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<p>The actual representation of values is determined by the machine architecture
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(strictly speaking, by the C implementation). The actual size can be accessed
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through the <code class="xref py py-attr docutils literal notranslate"><span class="pre">itemsize</span></code> attribute.</p>
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<p>The module defines the following type:</p>
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<dl class="class">
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<dt id="array.array">
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<em class="property">class </em><code class="descclassname">array.</code><code class="descname">array</code><span class="sig-paren">(</span><em>typecode</em><span class="optional">[</span>, <em>initializer</em><span class="optional">]</span><span class="sig-paren">)</span><a class="headerlink" href="#array.array" title="Permalink to this definition">¶</a></dt>
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<dd><p>A new array whose items are restricted by <em>typecode</em>, and initialized
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from the optional <em>initializer</em> value, which must be a list, a
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<a class="reference internal" href="../glossary.html#term-bytes-like-object"><span class="xref std std-term">bytes-like object</span></a>, or iterable over elements of the
|
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appropriate type.</p>
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<p>If given a list or string, the initializer is passed to the new array’s
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<a class="reference internal" href="#array.array.fromlist" title="array.array.fromlist"><code class="xref py py-meth docutils literal notranslate"><span class="pre">fromlist()</span></code></a>, <a class="reference internal" href="#array.array.frombytes" title="array.array.frombytes"><code class="xref py py-meth docutils literal notranslate"><span class="pre">frombytes()</span></code></a>, or <a class="reference internal" href="#array.array.fromunicode" title="array.array.fromunicode"><code class="xref py py-meth docutils literal notranslate"><span class="pre">fromunicode()</span></code></a> method (see below)
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to add initial items to the array. Otherwise, the iterable initializer is
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passed to the <a class="reference internal" href="#array.array.extend" title="array.array.extend"><code class="xref py py-meth docutils literal notranslate"><span class="pre">extend()</span></code></a> method.</p>
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</dd></dl>
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<dl class="data">
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<dt id="array.typecodes">
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<code class="descclassname">array.</code><code class="descname">typecodes</code><a class="headerlink" href="#array.typecodes" title="Permalink to this definition">¶</a></dt>
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<dd><p>A string with all available type codes.</p>
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</dd></dl>
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<p>Array objects support the ordinary sequence operations of indexing, slicing,
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concatenation, and multiplication. When using slice assignment, the assigned
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value must be an array object with the same type code; in all other cases,
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<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. Array objects also implement the buffer interface,
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and may be used wherever <a class="reference internal" href="../glossary.html#term-bytes-like-object"><span class="xref std std-term">bytes-like objects</span></a> are supported.</p>
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<p>The following data items and methods are also supported:</p>
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<dl class="attribute">
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<dt id="array.array.typecode">
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<code class="descclassname">array.</code><code class="descname">typecode</code><a class="headerlink" href="#array.array.typecode" title="Permalink to this definition">¶</a></dt>
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<dd><p>The typecode character used to create the array.</p>
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</dd></dl>
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<dl class="attribute">
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<dt id="array.array.itemsize">
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<code class="descclassname">array.</code><code class="descname">itemsize</code><a class="headerlink" href="#array.array.itemsize" title="Permalink to this definition">¶</a></dt>
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<dd><p>The length in bytes of one array item in the internal representation.</p>
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</dd></dl>
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<dl class="method">
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<dt id="array.array.append">
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<code class="descclassname">array.</code><code class="descname">append</code><span class="sig-paren">(</span><em>x</em><span class="sig-paren">)</span><a class="headerlink" href="#array.array.append" title="Permalink to this definition">¶</a></dt>
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<dd><p>Append a new item with value <em>x</em> to the end of the array.</p>
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</dd></dl>
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<dl class="method">
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<dt id="array.array.buffer_info">
|
|||
|
|
<code class="descclassname">array.</code><code class="descname">buffer_info</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#array.array.buffer_info" title="Permalink to this definition">¶</a></dt>
|
|||
|
|
<dd><p>Return a tuple <code class="docutils literal notranslate"><span class="pre">(address,</span> <span class="pre">length)</span></code> giving the current memory address and the
|
|||
|
|
length in elements of the buffer used to hold array’s contents. The size of the
|
|||
|
|
memory buffer in bytes can be computed as <code class="docutils literal notranslate"><span class="pre">array.buffer_info()[1]</span> <span class="pre">*</span>
|
|||
|
|
<span class="pre">array.itemsize</span></code>. This is occasionally useful when working with low-level (and
|
|||
|
|
inherently unsafe) I/O interfaces that require memory addresses, such as certain
|
|||
|
|
<code class="xref c c-func docutils literal notranslate"><span class="pre">ioctl()</span></code> operations. The returned numbers are valid as long as the array
|
|||
|
|
exists and no length-changing operations are applied to it.</p>
|
|||
|
|
<div class="admonition note">
|
|||
|
|
<p class="admonition-title">Note</p>
|
|||
|
|
<p>When using array objects from code written in C or C++ (the only way to
|
|||
|
|
effectively make use of this information), it makes more sense to use the buffer
|
|||
|
|
interface supported by array objects. This method is maintained for backward
|
|||
|
|
compatibility and should be avoided in new code. The buffer interface is
|
|||
|
|
documented in <a class="reference internal" href="../c-api/buffer.html#bufferobjects"><span class="std std-ref">Buffer Protocol</span></a>.</p>
|
|||
|
|
</div>
|
|||
|
|
</dd></dl>
|
|||
|
|
|
|||
|
|
<dl class="method">
|
|||
|
|
<dt id="array.array.byteswap">
|
|||
|
|
<code class="descclassname">array.</code><code class="descname">byteswap</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#array.array.byteswap" title="Permalink to this definition">¶</a></dt>
|
|||
|
|
<dd><p>“Byteswap” all items of the array. This is only supported for values which are
|
|||
|
|
1, 2, 4, or 8 bytes in size; for other types of values, <a class="reference internal" href="exceptions.html#RuntimeError" title="RuntimeError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">RuntimeError</span></code></a> is
|
|||
|
|
raised. It is useful when reading data from a file written on a machine with a
|
|||
|
|
different byte order.</p>
|
|||
|
|
</dd></dl>
|
|||
|
|
|
|||
|
|
<dl class="method">
|
|||
|
|
<dt id="array.array.count">
|
|||
|
|
<code class="descclassname">array.</code><code class="descname">count</code><span class="sig-paren">(</span><em>x</em><span class="sig-paren">)</span><a class="headerlink" href="#array.array.count" title="Permalink to this definition">¶</a></dt>
|
|||
|
|
<dd><p>Return the number of occurrences of <em>x</em> in the array.</p>
|
|||
|
|
</dd></dl>
|
|||
|
|
|
|||
|
|
<dl class="method">
|
|||
|
|
<dt id="array.array.extend">
|
|||
|
|
<code class="descclassname">array.</code><code class="descname">extend</code><span class="sig-paren">(</span><em>iterable</em><span class="sig-paren">)</span><a class="headerlink" href="#array.array.extend" title="Permalink to this definition">¶</a></dt>
|
|||
|
|
<dd><p>Append items from <em>iterable</em> to the end of the array. If <em>iterable</em> is another
|
|||
|
|
array, it must have <em>exactly</em> the same type code; if not, <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. If <em>iterable</em> is not an array, it must be iterable and its elements
|
|||
|
|
must be the right type to be appended to the array.</p>
|
|||
|
|
</dd></dl>
|
|||
|
|
|
|||
|
|
<dl class="method">
|
|||
|
|
<dt id="array.array.frombytes">
|
|||
|
|
<code class="descclassname">array.</code><code class="descname">frombytes</code><span class="sig-paren">(</span><em>s</em><span class="sig-paren">)</span><a class="headerlink" href="#array.array.frombytes" title="Permalink to this definition">¶</a></dt>
|
|||
|
|
<dd><p>Appends items from the string, interpreting the string as an array of machine
|
|||
|
|
values (as if it had been read from a file using the <a class="reference internal" href="#array.array.fromfile" title="array.array.fromfile"><code class="xref py py-meth docutils literal notranslate"><span class="pre">fromfile()</span></code></a> method).</p>
|
|||
|
|
<div class="versionadded">
|
|||
|
|
<p><span class="versionmodified added">New in version 3.2: </span><a class="reference internal" href="#array.array.fromstring" title="array.array.fromstring"><code class="xref py py-meth docutils literal notranslate"><span class="pre">fromstring()</span></code></a> is renamed to <a class="reference internal" href="#array.array.frombytes" title="array.array.frombytes"><code class="xref py py-meth docutils literal notranslate"><span class="pre">frombytes()</span></code></a> for clarity.</p>
|
|||
|
|
</div>
|
|||
|
|
</dd></dl>
|
|||
|
|
|
|||
|
|
<dl class="method">
|
|||
|
|
<dt id="array.array.fromfile">
|
|||
|
|
<code class="descclassname">array.</code><code class="descname">fromfile</code><span class="sig-paren">(</span><em>f</em>, <em>n</em><span class="sig-paren">)</span><a class="headerlink" href="#array.array.fromfile" title="Permalink to this definition">¶</a></dt>
|
|||
|
|
<dd><p>Read <em>n</em> items (as machine values) from the <a class="reference internal" href="../glossary.html#term-file-object"><span class="xref std std-term">file object</span></a> <em>f</em> and append
|
|||
|
|
them to the end of the array. If less than <em>n</em> items are available,
|
|||
|
|
<a class="reference internal" href="exceptions.html#EOFError" title="EOFError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">EOFError</span></code></a> is raised, but the items that were available are still
|
|||
|
|
inserted into the array. <em>f</em> must be a real built-in file object; something
|
|||
|
|
else with a <code class="xref py py-meth docutils literal notranslate"><span class="pre">read()</span></code> method won’t do.</p>
|
|||
|
|
</dd></dl>
|
|||
|
|
|
|||
|
|
<dl class="method">
|
|||
|
|
<dt id="array.array.fromlist">
|
|||
|
|
<code class="descclassname">array.</code><code class="descname">fromlist</code><span class="sig-paren">(</span><em>list</em><span class="sig-paren">)</span><a class="headerlink" href="#array.array.fromlist" title="Permalink to this definition">¶</a></dt>
|
|||
|
|
<dd><p>Append items from the list. This is equivalent to <code class="docutils literal notranslate"><span class="pre">for</span> <span class="pre">x</span> <span class="pre">in</span> <span class="pre">list:</span>
|
|||
|
|
<span class="pre">a.append(x)</span></code> except that if there is a type error, the array is unchanged.</p>
|
|||
|
|
</dd></dl>
|
|||
|
|
|
|||
|
|
<dl class="method">
|
|||
|
|
<dt id="array.array.fromstring">
|
|||
|
|
<code class="descclassname">array.</code><code class="descname">fromstring</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#array.array.fromstring" title="Permalink to this definition">¶</a></dt>
|
|||
|
|
<dd><p>Deprecated alias for <a class="reference internal" href="#array.array.frombytes" title="array.array.frombytes"><code class="xref py py-meth docutils literal notranslate"><span class="pre">frombytes()</span></code></a>.</p>
|
|||
|
|
</dd></dl>
|
|||
|
|
|
|||
|
|
<dl class="method">
|
|||
|
|
<dt id="array.array.fromunicode">
|
|||
|
|
<code class="descclassname">array.</code><code class="descname">fromunicode</code><span class="sig-paren">(</span><em>s</em><span class="sig-paren">)</span><a class="headerlink" href="#array.array.fromunicode" title="Permalink to this definition">¶</a></dt>
|
|||
|
|
<dd><p>Extends this array with data from the given unicode string. The array must
|
|||
|
|
be a type <code class="docutils literal notranslate"><span class="pre">'u'</span></code> array; otherwise 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> is raised. Use
|
|||
|
|
<code class="docutils literal notranslate"><span class="pre">array.frombytes(unicodestring.encode(enc))</span></code> to append Unicode data to an
|
|||
|
|
array of some other type.</p>
|
|||
|
|
</dd></dl>
|
|||
|
|
|
|||
|
|
<dl class="method">
|
|||
|
|
<dt id="array.array.index">
|
|||
|
|
<code class="descclassname">array.</code><code class="descname">index</code><span class="sig-paren">(</span><em>x</em><span class="sig-paren">)</span><a class="headerlink" href="#array.array.index" title="Permalink to this definition">¶</a></dt>
|
|||
|
|
<dd><p>Return the smallest <em>i</em> such that <em>i</em> is the index of the first occurrence of
|
|||
|
|
<em>x</em> in the array.</p>
|
|||
|
|
</dd></dl>
|
|||
|
|
|
|||
|
|
<dl class="method">
|
|||
|
|
<dt id="array.array.insert">
|
|||
|
|
<code class="descclassname">array.</code><code class="descname">insert</code><span class="sig-paren">(</span><em>i</em>, <em>x</em><span class="sig-paren">)</span><a class="headerlink" href="#array.array.insert" title="Permalink to this definition">¶</a></dt>
|
|||
|
|
<dd><p>Insert a new item with value <em>x</em> in the array before position <em>i</em>. Negative
|
|||
|
|
values are treated as being relative to the end of the array.</p>
|
|||
|
|
</dd></dl>
|
|||
|
|
|
|||
|
|
<dl class="method">
|
|||
|
|
<dt id="array.array.pop">
|
|||
|
|
<code class="descclassname">array.</code><code class="descname">pop</code><span class="sig-paren">(</span><span class="optional">[</span><em>i</em><span class="optional">]</span><span class="sig-paren">)</span><a class="headerlink" href="#array.array.pop" title="Permalink to this definition">¶</a></dt>
|
|||
|
|
<dd><p>Removes the item with the index <em>i</em> from the array and returns it. The optional
|
|||
|
|
argument defaults to <code class="docutils literal notranslate"><span class="pre">-1</span></code>, so that by default the last item is removed and
|
|||
|
|
returned.</p>
|
|||
|
|
</dd></dl>
|
|||
|
|
|
|||
|
|
<dl class="method">
|
|||
|
|
<dt id="array.array.remove">
|
|||
|
|
<code class="descclassname">array.</code><code class="descname">remove</code><span class="sig-paren">(</span><em>x</em><span class="sig-paren">)</span><a class="headerlink" href="#array.array.remove" title="Permalink to this definition">¶</a></dt>
|
|||
|
|
<dd><p>Remove the first occurrence of <em>x</em> from the array.</p>
|
|||
|
|
</dd></dl>
|
|||
|
|
|
|||
|
|
<dl class="method">
|
|||
|
|
<dt id="array.array.reverse">
|
|||
|
|
<code class="descclassname">array.</code><code class="descname">reverse</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#array.array.reverse" title="Permalink to this definition">¶</a></dt>
|
|||
|
|
<dd><p>Reverse the order of the items in the array.</p>
|
|||
|
|
</dd></dl>
|
|||
|
|
|
|||
|
|
<dl class="method">
|
|||
|
|
<dt id="array.array.tobytes">
|
|||
|
|
<code class="descclassname">array.</code><code class="descname">tobytes</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#array.array.tobytes" title="Permalink to this definition">¶</a></dt>
|
|||
|
|
<dd><p>Convert the array to an array of machine values and return the bytes
|
|||
|
|
representation (the same sequence of bytes that would be written to a file by
|
|||
|
|
the <a class="reference internal" href="#array.array.tofile" title="array.array.tofile"><code class="xref py py-meth docutils literal notranslate"><span class="pre">tofile()</span></code></a> method.)</p>
|
|||
|
|
<div class="versionadded">
|
|||
|
|
<p><span class="versionmodified added">New in version 3.2: </span><a class="reference internal" href="#array.array.tostring" title="array.array.tostring"><code class="xref py py-meth docutils literal notranslate"><span class="pre">tostring()</span></code></a> is renamed to <a class="reference internal" href="#array.array.tobytes" title="array.array.tobytes"><code class="xref py py-meth docutils literal notranslate"><span class="pre">tobytes()</span></code></a> for clarity.</p>
|
|||
|
|
</div>
|
|||
|
|
</dd></dl>
|
|||
|
|
|
|||
|
|
<dl class="method">
|
|||
|
|
<dt id="array.array.tofile">
|
|||
|
|
<code class="descclassname">array.</code><code class="descname">tofile</code><span class="sig-paren">(</span><em>f</em><span class="sig-paren">)</span><a class="headerlink" href="#array.array.tofile" title="Permalink to this definition">¶</a></dt>
|
|||
|
|
<dd><p>Write all items (as machine values) to the <a class="reference internal" href="../glossary.html#term-file-object"><span class="xref std std-term">file object</span></a> <em>f</em>.</p>
|
|||
|
|
</dd></dl>
|
|||
|
|
|
|||
|
|
<dl class="method">
|
|||
|
|
<dt id="array.array.tolist">
|
|||
|
|
<code class="descclassname">array.</code><code class="descname">tolist</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#array.array.tolist" title="Permalink to this definition">¶</a></dt>
|
|||
|
|
<dd><p>Convert the array to an ordinary list with the same items.</p>
|
|||
|
|
</dd></dl>
|
|||
|
|
|
|||
|
|
<dl class="method">
|
|||
|
|
<dt id="array.array.tostring">
|
|||
|
|
<code class="descclassname">array.</code><code class="descname">tostring</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#array.array.tostring" title="Permalink to this definition">¶</a></dt>
|
|||
|
|
<dd><p>Deprecated alias for <a class="reference internal" href="#array.array.tobytes" title="array.array.tobytes"><code class="xref py py-meth docutils literal notranslate"><span class="pre">tobytes()</span></code></a>.</p>
|
|||
|
|
</dd></dl>
|
|||
|
|
|
|||
|
|
<dl class="method">
|
|||
|
|
<dt id="array.array.tounicode">
|
|||
|
|
<code class="descclassname">array.</code><code class="descname">tounicode</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#array.array.tounicode" title="Permalink to this definition">¶</a></dt>
|
|||
|
|
<dd><p>Convert the array to a unicode string. The array must be a type <code class="docutils literal notranslate"><span class="pre">'u'</span></code> array;
|
|||
|
|
otherwise 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> is raised. Use <code class="docutils literal notranslate"><span class="pre">array.tobytes().decode(enc)</span></code> to
|
|||
|
|
obtain a unicode string from an array of some other type.</p>
|
|||
|
|
</dd></dl>
|
|||
|
|
|
|||
|
|
<p>When an array object is printed or converted to a string, it is represented as
|
|||
|
|
<code class="docutils literal notranslate"><span class="pre">array(typecode,</span> <span class="pre">initializer)</span></code>. The <em>initializer</em> is omitted if the array is
|
|||
|
|
empty, otherwise it is a string if the <em>typecode</em> is <code class="docutils literal notranslate"><span class="pre">'u'</span></code>, otherwise it is a
|
|||
|
|
list of numbers. The string is guaranteed to be able to be converted back to an
|
|||
|
|
array with the same type and value using <a class="reference internal" href="functions.html#eval" title="eval"><code class="xref py py-func docutils literal notranslate"><span class="pre">eval()</span></code></a>, so long as the
|
|||
|
|
<a class="reference internal" href="#array.array" title="array.array"><code class="xref py py-class docutils literal notranslate"><span class="pre">array</span></code></a> class has been imported using <code class="docutils literal notranslate"><span class="pre">from</span> <span class="pre">array</span> <span class="pre">import</span> <span class="pre">array</span></code>.
|
|||
|
|
Examples:</p>
|
|||
|
|
<div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="n">array</span><span class="p">(</span><span class="s1">'l'</span><span class="p">)</span>
|
|||
|
|
<span class="n">array</span><span class="p">(</span><span class="s1">'u'</span><span class="p">,</span> <span class="s1">'hello </span><span class="se">\u2641</span><span class="s1">'</span><span class="p">)</span>
|
|||
|
|
<span class="n">array</span><span class="p">(</span><span class="s1">'l'</span><span class="p">,</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="mi">4</span><span class="p">,</span> <span class="mi">5</span><span class="p">])</span>
|
|||
|
|
<span class="n">array</span><span class="p">(</span><span class="s1">'d'</span><span class="p">,</span> <span class="p">[</span><span class="mf">1.0</span><span class="p">,</span> <span class="mf">2.0</span><span class="p">,</span> <span class="mf">3.14</span><span class="p">])</span>
|
|||
|
|
</pre></div>
|
|||
|
|
</div>
|
|||
|
|
<div class="admonition seealso">
|
|||
|
|
<p class="admonition-title">See also</p>
|
|||
|
|
<dl class="simple">
|
|||
|
|
<dt>Module <a class="reference internal" href="struct.html#module-struct" title="struct: Interpret bytes as packed binary data."><code class="xref py py-mod docutils literal notranslate"><span class="pre">struct</span></code></a></dt><dd><p>Packing and unpacking of heterogeneous binary data.</p>
|
|||
|
|
</dd>
|
|||
|
|
<dt>Module <a class="reference internal" href="xdrlib.html#module-xdrlib" title="xdrlib: Encoders and decoders for the External Data Representation (XDR)."><code class="xref py py-mod docutils literal notranslate"><span class="pre">xdrlib</span></code></a></dt><dd><p>Packing and unpacking of External Data Representation (XDR) data as used in some
|
|||
|
|
remote procedure call systems.</p>
|
|||
|
|
</dd>
|
|||
|
|
<dt><a class="reference external" href="https://docs.scipy.org/doc/">The Numerical Python Documentation</a></dt><dd><p>The Numeric Python extension (NumPy) defines another array type; see
|
|||
|
|
<a class="reference external" href="http://www.numpy.org/">http://www.numpy.org/</a> for further information about Numerical Python.</p>
|
|||
|
|
</dd>
|
|||
|
|
</dl>
|
|||
|
|
</div>
|
|||
|
|
</div>
|
|||
|
|
|
|||
|
|
|
|||
|
|
</div>
|
|||
|
|
</div>
|
|||
|
|
</div>
|
|||
|
|
<div class="sphinxsidebar" role="navigation" aria-label="main navigation">
|
|||
|
|
<div class="sphinxsidebarwrapper">
|
|||
|
|
<h4>Previous topic</h4>
|
|||
|
|
<p class="topless"><a href="bisect.html"
|
|||
|
|
title="previous chapter"><code class="xref py py-mod docutils literal notranslate"><span class="pre">bisect</span></code> — Array bisection algorithm</a></p>
|
|||
|
|
<h4>Next topic</h4>
|
|||
|
|
<p class="topless"><a href="weakref.html"
|
|||
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