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<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
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<title>Object Interface</title>
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<link rel="home" href="../index.html" title="Boost.Python Tutorial">
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<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
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<table cellpadding="2" width="100%"><tr><td valign="top"><img alt="" width="" height="" src="../../images/bpl.png"></td></tr></table>
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<a accesskey="p" href="functions.html"><img src="../../images/prev.png" alt="Prev"></a><a accesskey="u" href="../index.html"><img src="../../images/up.png" alt="Up"></a><a accesskey="h" href="../index.html"><img src="../../images/home.png" alt="Home"></a><a accesskey="n" href="embedding.html"><img src="../../images/next.png" alt="Next"></a>
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</div>
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<div class="section">
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<div class="titlepage"><div><div><h2 class="title" style="clear: both">
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<a name="tutorial.object"></a><a class="link" href="object.html" title="Object Interface">Object Interface</a>
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</h2></div></div></div>
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<div class="toc"><dl class="toc">
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<dt><span class="section"><a href="object.html#tutorial.object.basic_interface">Basic Interface</a></span></dt>
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<dt><span class="section"><a href="object.html#tutorial.object.derived_object_types">Derived Object
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types</a></span></dt>
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<dt><span class="section"><a href="object.html#tutorial.object.extracting_c_objects">Extracting C++
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objects</a></span></dt>
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<dt><span class="section"><a href="object.html#tutorial.object.enums">Enums</a></span></dt>
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<dt><span class="section"><a href="object.html#tutorial.object.creating_python_object">Creating <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">python</span><span class="special">::</span><span class="identifier">object</span></code>
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from <code class="computeroutput"><span class="identifier">PyObject</span><span class="special">*</span></code></a></span></dt>
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</dl></div>
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<p>
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Python is dynamically typed, unlike C++ which is statically typed. Python variables
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may hold an integer, a float, list, dict, tuple, str, long etc., among other
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things. In the viewpoint of Boost.Python and C++, these Pythonic variables
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are just instances of class <code class="literal">object</code>. We will see in this
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chapter how to deal with Python objects.
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</p>
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<p>
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As mentioned, one of the goals of Boost.Python is to provide a bidirectional
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mapping between C++ and Python while maintaining the Python feel. Boost.Python
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C++ <code class="literal">object</code>s are as close as possible to Python. This should
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minimize the learning curve significantly.
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</p>
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<p>
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<span class="inlinemediaobject"><img src="../../images/python.png"></span>
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</p>
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<div class="section">
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<div class="titlepage"><div><div><h3 class="title">
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<a name="tutorial.object.basic_interface"></a><a class="link" href="object.html#tutorial.object.basic_interface" title="Basic Interface">Basic Interface</a>
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</h3></div></div></div>
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<p>
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Class <code class="literal">object</code> wraps <code class="literal">PyObject*</code>. All the
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intricacies of dealing with <code class="literal">PyObject</code>s such as managing
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reference counting are handled by the <code class="literal">object</code> class. C++
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object interoperability is seamless. Boost.Python C++ <code class="literal">object</code>s
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can in fact be explicitly constructed from any C++ object.
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</p>
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<p>
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To illustrate, this Python code snippet:
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</p>
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<pre class="programlisting"><span class="keyword">def</span> <span class="identifier">f</span><span class="special">(</span><span class="identifier">x</span><span class="special">,</span> <span class="identifier">y</span><span class="special">):</span>
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<span class="keyword">if</span> <span class="special">(</span><span class="identifier">y</span> <span class="special">==</span> <span class="string">'foo'</span><span class="special">):</span>
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<span class="identifier">x</span><span class="special">[</span><span class="number">3</span><span class="special">:</span><span class="number">7</span><span class="special">]</span> <span class="special">=</span> <span class="string">'bar'</span>
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<span class="keyword">else</span><span class="special">:</span>
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<span class="identifier">x</span><span class="special">.</span><span class="identifier">items</span> <span class="special">+=</span> <span class="identifier">y</span><span class="special">(</span><span class="number">3</span><span class="special">,</span> <span class="identifier">x</span><span class="special">)</span>
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<span class="keyword">return</span> <span class="identifier">x</span>
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<span class="keyword">def</span> <span class="identifier">getfunc</span><span class="special">():</span>
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<span class="keyword">return</span> <span class="identifier">f</span><span class="special">;</span>
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</pre>
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<p>
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Can be rewritten in C++ using Boost.Python facilities this way:
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</p>
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<pre class="programlisting"><span class="identifier">object</span> <span class="identifier">f</span><span class="special">(</span><span class="identifier">object</span> <span class="identifier">x</span><span class="special">,</span> <span class="identifier">object</span> <span class="identifier">y</span><span class="special">)</span> <span class="special">{</span>
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<span class="keyword">if</span> <span class="special">(</span><span class="identifier">y</span> <span class="special">==</span> <span class="string">"foo"</span><span class="special">)</span>
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<span class="identifier">x</span><span class="special">.</span><span class="identifier">slice</span><span class="special">(</span><span class="number">3</span><span class="special">,</span><span class="number">7</span><span class="special">)</span> <span class="special">=</span> <span class="string">"bar"</span><span class="special">;</span>
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<span class="keyword">else</span>
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<span class="identifier">x</span><span class="special">.</span><span class="identifier">attr</span><span class="special">(</span><span class="string">"items"</span><span class="special">)</span> <span class="special">+=</span> <span class="identifier">y</span><span class="special">(</span><span class="number">3</span><span class="special">,</span> <span class="identifier">x</span><span class="special">);</span>
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<span class="keyword">return</span> <span class="identifier">x</span><span class="special">;</span>
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<span class="special">}</span>
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<span class="identifier">object</span> <span class="identifier">getfunc</span><span class="special">()</span> <span class="special">{</span>
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<span class="keyword">return</span> <span class="identifier">object</span><span class="special">(</span><span class="identifier">f</span><span class="special">);</span>
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<span class="special">}</span>
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</pre>
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<p>
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Apart from cosmetic differences due to the fact that we are writing the code
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in C++, the look and feel should be immediately apparent to the Python coder.
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</p>
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</div>
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<div class="section">
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<div class="titlepage"><div><div><h3 class="title">
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<a name="tutorial.object.derived_object_types"></a><a class="link" href="object.html#tutorial.object.derived_object_types" title="Derived Object types">Derived Object
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types</a>
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</h3></div></div></div>
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<p>
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Boost.Python comes with a set of derived <code class="literal">object</code> types
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corresponding to that of Python's:
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</p>
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<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
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<li class="listitem">
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list
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</li>
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<li class="listitem">
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dict
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</li>
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<li class="listitem">
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tuple
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</li>
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<li class="listitem">
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str
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</li>
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<li class="listitem">
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long_
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</li>
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<li class="listitem">
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enum
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</li>
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</ul></div>
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<p>
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These derived <code class="literal">object</code> types act like real Python types.
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For instance:
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</p>
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<pre class="programlisting"><span class="identifier">str</span><span class="special">(</span><span class="number">1</span><span class="special">)</span> <span class="special">==></span> <span class="string">"1"</span>
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</pre>
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<p>
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Wherever appropriate, a particular derived <code class="literal">object</code> has
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corresponding Python type's methods. For instance, <code class="literal">dict</code>
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has a <code class="literal">keys()</code> method:
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</p>
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<pre class="programlisting"><span class="identifier">d</span><span class="special">.</span><span class="identifier">keys</span><span class="special">()</span>
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</pre>
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<p>
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<code class="literal">make_tuple</code> is provided for declaring <span class="emphasis"><em>tuple literals</em></span>.
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Example:
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</p>
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<pre class="programlisting"><span class="identifier">make_tuple</span><span class="special">(</span><span class="number">123</span><span class="special">,</span> <span class="char">'D'</span><span class="special">,</span> <span class="string">"Hello, World"</span><span class="special">,</span> <span class="number">0.0</span><span class="special">);</span>
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</pre>
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<p>
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In C++, when Boost.Python <code class="literal">object</code>s are used as arguments
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to functions, subtype matching is required. For example, when a function
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<code class="literal">f</code>, as declared below, is wrapped, it will only accept
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instances of Python's <code class="literal">str</code> type and subtypes.
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</p>
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<pre class="programlisting"><span class="keyword">void</span> <span class="identifier">f</span><span class="special">(</span><span class="identifier">str</span> <span class="identifier">name</span><span class="special">)</span>
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<span class="special">{</span>
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<span class="identifier">object</span> <span class="identifier">n2</span> <span class="special">=</span> <span class="identifier">name</span><span class="special">.</span><span class="identifier">attr</span><span class="special">(</span><span class="string">"upper"</span><span class="special">)();</span> <span class="comment">// NAME = name.upper()</span>
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<span class="identifier">str</span> <span class="identifier">NAME</span> <span class="special">=</span> <span class="identifier">name</span><span class="special">.</span><span class="identifier">upper</span><span class="special">();</span> <span class="comment">// better</span>
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<span class="identifier">object</span> <span class="identifier">msg</span> <span class="special">=</span> <span class="string">"%s is bigger than %s"</span> <span class="special">%</span> <span class="identifier">make_tuple</span><span class="special">(</span><span class="identifier">NAME</span><span class="special">,</span><span class="identifier">name</span><span class="special">);</span>
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<span class="special">}</span>
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</pre>
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<p>
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In finer detail:
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</p>
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<pre class="programlisting"><span class="identifier">str</span> <span class="identifier">NAME</span> <span class="special">=</span> <span class="identifier">name</span><span class="special">.</span><span class="identifier">upper</span><span class="special">();</span>
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</pre>
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<p>
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Illustrates that we provide versions of the str type's methods as C++ member
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functions.
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</p>
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<pre class="programlisting"><span class="identifier">object</span> <span class="identifier">msg</span> <span class="special">=</span> <span class="string">"%s is bigger than %s"</span> <span class="special">%</span> <span class="identifier">make_tuple</span><span class="special">(</span><span class="identifier">NAME</span><span class="special">,</span><span class="identifier">name</span><span class="special">);</span>
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</pre>
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<p>
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Demonstrates that you can write the C++ equivalent of <code class="literal">"format"
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% x,y,z</code> in Python, which is useful since there's no easy way to
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do that in std C++.
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</p>
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<div class="blurb">
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<div class="titlepage"></div>
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<p>
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<span class="inlinemediaobject"><img src="../../images/alert.png"></span>
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<span class="bold"><strong>Beware</strong></span> the common pitfall of forgetting
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that the constructors of most of Python's mutable types make copies, just
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as in Python.
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</p>
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</div>
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<p>
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Python:
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</p>
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<pre class="programlisting"><span class="special">>>></span> <span class="identifier">d</span> <span class="special">=</span> <span class="identifier">dict</span><span class="special">(</span><span class="identifier">x</span><span class="special">.</span><span class="identifier">__dict__</span><span class="special">)</span> <span class="comment"># copies x.__dict__</span>
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<span class="special">>>></span> <span class="identifier">d</span><span class="special">[</span><span class="string">'whatever'</span><span class="special">]</span> <span class="special">=</span> <span class="number">3</span> <span class="comment"># modifies the copy</span>
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</pre>
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<p>
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C++:
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</p>
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<pre class="programlisting"><span class="identifier">dict</span> <span class="identifier">d</span><span class="special">(</span><span class="identifier">x</span><span class="special">.</span><span class="identifier">attr</span><span class="special">(</span><span class="string">"__dict__"</span><span class="special">));</span> <span class="comment">// copies x.__dict__</span>
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<span class="identifier">d</span><span class="special">[</span><span class="char">'whatever'</span><span class="special">]</span> <span class="special">=</span> <span class="number">3</span><span class="special">;</span> <span class="comment">// modifies the copy</span>
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</pre>
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<h3>
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<a name="tutorial.object.derived_object_types.h0"></a>
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<span class="phrase"><a name="tutorial.object.derived_object_types.class_t_as_objects"></a></span><a class="link" href="object.html#tutorial.object.derived_object_types.class_t_as_objects">class_<T>
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as objects</a>
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</h3>
|
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<p>
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Due to the dynamic nature of Boost.Python objects, any <code class="literal">class_<T></code>
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may also be one of these types! The following code snippet wraps the class
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(type) object.
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</p>
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<p>
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We can use this to create wrapped instances. Example:
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</p>
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<pre class="programlisting"><span class="identifier">object</span> <span class="identifier">vec345</span> <span class="special">=</span> <span class="special">(</span>
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<span class="identifier">class_</span><span class="special"><</span><span class="identifier">Vec2</span><span class="special">>(</span><span class="string">"Vec2"</span><span class="special">,</span> <span class="identifier">init</span><span class="special"><</span><span class="keyword">double</span><span class="special">,</span> <span class="keyword">double</span><span class="special">>())</span>
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<span class="special">.</span><span class="identifier">def_readonly</span><span class="special">(</span><span class="string">"length"</span><span class="special">,</span> <span class="special">&</span><span class="identifier">Point</span><span class="special">::</span><span class="identifier">length</span><span class="special">)</span>
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<span class="special">.</span><span class="identifier">def_readonly</span><span class="special">(</span><span class="string">"angle"</span><span class="special">,</span> <span class="special">&</span><span class="identifier">Point</span><span class="special">::</span><span class="identifier">angle</span><span class="special">)</span>
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<span class="special">)(</span><span class="number">3.0</span><span class="special">,</span> <span class="number">4.0</span><span class="special">);</span>
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<span class="identifier">assert</span><span class="special">(</span><span class="identifier">vec345</span><span class="special">.</span><span class="identifier">attr</span><span class="special">(</span><span class="string">"length"</span><span class="special">)</span> <span class="special">==</span> <span class="number">5.0</span><span class="special">);</span>
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</pre>
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</div>
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<div class="section">
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<div class="titlepage"><div><div><h3 class="title">
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<a name="tutorial.object.extracting_c_objects"></a><a class="link" href="object.html#tutorial.object.extracting_c_objects" title="Extracting C++ objects">Extracting C++
|
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objects</a>
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</h3></div></div></div>
|
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<p>
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At some point, we will need to get C++ values out of object instances. This
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can be achieved with the <code class="literal">extract<T></code> function. Consider
|
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the following:
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</p>
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<pre class="programlisting"><span class="keyword">double</span> <span class="identifier">x</span> <span class="special">=</span> <span class="identifier">o</span><span class="special">.</span><span class="identifier">attr</span><span class="special">(</span><span class="string">"length"</span><span class="special">);</span> <span class="comment">// compile error</span>
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</pre>
|
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<p>
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In the code above, we got a compiler error because Boost.Python <code class="literal">object</code>
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can't be implicitly converted to <code class="literal">double</code>s. Instead, what
|
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we wanted to do above can be achieved by writing:
|
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</p>
|
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<pre class="programlisting"><span class="keyword">double</span> <span class="identifier">l</span> <span class="special">=</span> <span class="identifier">extract</span><span class="special"><</span><span class="keyword">double</span><span class="special">>(</span><span class="identifier">o</span><span class="special">.</span><span class="identifier">attr</span><span class="special">(</span><span class="string">"length"</span><span class="special">));</span>
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<span class="identifier">Vec2</span><span class="special">&</span> <span class="identifier">v</span> <span class="special">=</span> <span class="identifier">extract</span><span class="special"><</span><span class="identifier">Vec2</span><span class="special">&>(</span><span class="identifier">o</span><span class="special">);</span>
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<span class="identifier">assert</span><span class="special">(</span><span class="identifier">l</span> <span class="special">==</span> <span class="identifier">v</span><span class="special">.</span><span class="identifier">length</span><span class="special">());</span>
|
|
</pre>
|
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<p>
|
|
The first line attempts to extract the "length" attribute of the
|
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Boost.Python <code class="literal">object</code>. The second line attempts to <span class="emphasis"><em>extract</em></span>
|
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the <code class="literal">Vec2</code> object from held by the Boost.Python <code class="literal">object</code>.
|
|
</p>
|
|
<p>
|
|
Take note that we said "attempt to" above. What if the Boost.Python
|
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<code class="literal">object</code> does not really hold a <code class="literal">Vec2</code>
|
|
type? This is certainly a possibility considering the dynamic nature of Python
|
|
<code class="literal">object</code>s. To be on the safe side, if the C++ type can't
|
|
be extracted, an appropriate exception is thrown. To avoid an exception,
|
|
we need to test for extractibility:
|
|
</p>
|
|
<pre class="programlisting"><span class="identifier">extract</span><span class="special"><</span><span class="identifier">Vec2</span><span class="special">&></span> <span class="identifier">x</span><span class="special">(</span><span class="identifier">o</span><span class="special">);</span>
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<span class="keyword">if</span> <span class="special">(</span><span class="identifier">x</span><span class="special">.</span><span class="identifier">check</span><span class="special">())</span> <span class="special">{</span>
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|
<span class="identifier">Vec2</span><span class="special">&</span> <span class="identifier">v</span> <span class="special">=</span> <span class="identifier">x</span><span class="special">();</span> <span class="special">...</span>
|
|
</pre>
|
|
<p>
|
|
<span class="inlinemediaobject"><img src="../../images/tip.png"></span>
|
|
The astute reader might have noticed that the <code class="literal">extract<T></code>
|
|
facility in fact solves the mutable copying problem:
|
|
</p>
|
|
<pre class="programlisting"><span class="identifier">dict</span> <span class="identifier">d</span> <span class="special">=</span> <span class="identifier">extract</span><span class="special"><</span><span class="identifier">dict</span><span class="special">>(</span><span class="identifier">x</span><span class="special">.</span><span class="identifier">attr</span><span class="special">(</span><span class="string">"__dict__"</span><span class="special">));</span>
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|
<span class="identifier">d</span><span class="special">[</span><span class="string">"whatever"</span><span class="special">]</span> <span class="special">=</span> <span class="number">3</span><span class="special">;</span> <span class="comment">// modifies x.__dict__ !</span>
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|
</pre>
|
|
</div>
|
|
<div class="section">
|
|
<div class="titlepage"><div><div><h3 class="title">
|
|
<a name="tutorial.object.enums"></a><a class="link" href="object.html#tutorial.object.enums" title="Enums">Enums</a>
|
|
</h3></div></div></div>
|
|
<p>
|
|
Boost.Python has a nifty facility to capture and wrap C++ enums. While Python
|
|
has no <code class="literal">enum</code> type, we'll often want to expose our C++ enums
|
|
to Python as an <code class="literal">int</code>. Boost.Python's enum facility makes
|
|
this easy while taking care of the proper conversions from Python's dynamic
|
|
typing to C++'s strong static typing (in C++, ints cannot be implicitly converted
|
|
to enums). To illustrate, given a C++ enum:
|
|
</p>
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|
<pre class="programlisting"><span class="keyword">enum</span> <span class="identifier">choice</span> <span class="special">{</span> <span class="identifier">red</span><span class="special">,</span> <span class="identifier">blue</span> <span class="special">};</span>
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|
</pre>
|
|
<p>
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|
the construct:
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|
</p>
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|
<pre class="programlisting"><span class="identifier">enum_</span><span class="special"><</span><span class="identifier">choice</span><span class="special">>(</span><span class="string">"choice"</span><span class="special">)</span>
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<span class="special">.</span><span class="identifier">value</span><span class="special">(</span><span class="string">"red"</span><span class="special">,</span> <span class="identifier">red</span><span class="special">)</span>
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|
<span class="special">.</span><span class="identifier">value</span><span class="special">(</span><span class="string">"blue"</span><span class="special">,</span> <span class="identifier">blue</span><span class="special">)</span>
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<span class="special">;</span>
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|
</pre>
|
|
<p>
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|
can be used to expose to Python. The new enum type is created in the current
|
|
<code class="literal">scope()</code>, which is usually the current module. The snippet
|
|
above creates a Python class derived from Python's <code class="literal">int</code>
|
|
type which is associated with the C++ type passed as its first parameter.
|
|
</p>
|
|
<div class="note"><table border="0" summary="Note">
|
|
<tr>
|
|
<td rowspan="2" align="center" valign="top" width="25"><img alt="[Note]" src="../../images/note.png"></td>
|
|
<th align="left">Note</th>
|
|
</tr>
|
|
<tr><td align="left" valign="top">
|
|
<p>
|
|
<span class="bold"><strong>what is a scope?</strong></span>
|
|
</p>
|
|
<p>
|
|
The scope is a class that has an associated global Python object which
|
|
controls the Python namespace in which new extension classes and wrapped
|
|
functions will be defined as attributes. Details can be found <a href="../../reference/high_level_components/boost_python_scope_hpp.html#high_level_components.boost_python_scope_hpp.class_scope" target="_top">here</a>.
|
|
</p>
|
|
</td></tr>
|
|
</table></div>
|
|
<p>
|
|
You can access those values in Python as
|
|
</p>
|
|
<pre class="programlisting"><span class="special">>>></span> <span class="identifier">my_module</span><span class="special">.</span><span class="identifier">choice</span><span class="special">.</span><span class="identifier">red</span>
|
|
<span class="identifier">my_module</span><span class="special">.</span><span class="identifier">choice</span><span class="special">.</span><span class="identifier">red</span>
|
|
</pre>
|
|
<p>
|
|
where my_module is the module where the enum is declared. You can also create
|
|
a new scope around a class:
|
|
</p>
|
|
<pre class="programlisting"><span class="identifier">scope</span> <span class="identifier">in_X</span> <span class="special">=</span> <span class="identifier">class_</span><span class="special"><</span><span class="identifier">X</span><span class="special">>(</span><span class="string">"X"</span><span class="special">)</span>
|
|
<span class="special">.</span><span class="identifier">def</span><span class="special">(</span> <span class="special">...</span> <span class="special">)</span>
|
|
<span class="special">.</span><span class="identifier">def</span><span class="special">(</span> <span class="special">...</span> <span class="special">)</span>
|
|
<span class="special">;</span>
|
|
|
|
<span class="comment">// Expose X::nested as X.nested</span>
|
|
<span class="identifier">enum_</span><span class="special"><</span><span class="identifier">X</span><span class="special">::</span><span class="identifier">nested</span><span class="special">>(</span><span class="string">"nested"</span><span class="special">)</span>
|
|
<span class="special">.</span><span class="identifier">value</span><span class="special">(</span><span class="string">"red"</span><span class="special">,</span> <span class="identifier">red</span><span class="special">)</span>
|
|
<span class="special">.</span><span class="identifier">value</span><span class="special">(</span><span class="string">"blue"</span><span class="special">,</span> <span class="identifier">blue</span><span class="special">)</span>
|
|
<span class="special">;</span>
|
|
</pre>
|
|
</div>
|
|
<div class="section">
|
|
<div class="titlepage"><div><div><h3 class="title">
|
|
<a name="tutorial.object.creating_python_object"></a><a class="link" href="object.html#tutorial.object.creating_python_object" title="Creating boost::python::object from PyObject*">Creating <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">python</span><span class="special">::</span><span class="identifier">object</span></code>
|
|
from <code class="computeroutput"><span class="identifier">PyObject</span><span class="special">*</span></code></a>
|
|
</h3></div></div></div>
|
|
<p>
|
|
When you want a <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">python</span><span class="special">::</span><span class="identifier">object</span></code> to manage a pointer to <code class="computeroutput"><span class="identifier">PyObject</span><span class="special">*</span></code>
|
|
pyobj one does:
|
|
</p>
|
|
<pre class="programlisting"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">python</span><span class="special">::</span><span class="identifier">object</span> <span class="identifier">o</span><span class="special">(</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">python</span><span class="special">::</span><span class="identifier">handle</span><span class="special"><>(</span><span class="identifier">pyobj</span><span class="special">));</span>
|
|
</pre>
|
|
<p>
|
|
In this case, the <code class="computeroutput"><span class="identifier">o</span></code> object,
|
|
manages the <code class="computeroutput"><span class="identifier">pyobj</span></code>, it won’t
|
|
increase the reference count on construction.
|
|
</p>
|
|
<p>
|
|
Otherwise, to use a borrowed reference:
|
|
</p>
|
|
<pre class="programlisting"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">python</span><span class="special">::</span><span class="identifier">object</span> <span class="identifier">o</span><span class="special">(</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">python</span><span class="special">::</span><span class="identifier">handle</span><span class="special"><>(</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">python</span><span class="special">::</span><span class="identifier">borrowed</span><span class="special">(</span><span class="identifier">pyobj</span><span class="special">)));</span>
|
|
</pre>
|
|
<p>
|
|
In this case, <code class="computeroutput"><span class="identifier">Py_INCREF</span></code> is
|
|
called, so <code class="computeroutput"><span class="identifier">pyobj</span></code> is not destructed
|
|
when object o goes out of scope.
|
|
</p>
|
|
</div>
|
|
</div>
|
|
<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
|
|
<td align="left"></td>
|
|
<td align="right"><div class="copyright-footer">Copyright © 2002-2005 Joel
|
|
de Guzman, David Abrahams<p>
|
|
Distributed under the Boost Software License, Version 1.0. (See accompanying
|
|
file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>
|
|
</p>
|
|
</div></td>
|
|
</tr></table>
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