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    <p>Ooh, this is tricky (and fun). SWIG <em>doesn't</em> recognize this as an opportunity to generate @property: I imagine it'd be all too easy to slip up and recognize lots of false positives if it weren't done really carefully. However, since SWIG won't do it in generating C++, it's still entirely possible to do this in Python using a small metaclass.</p> <p>So, below, let's say we have a Math class that lets us set and get an integer variable named "pi". Then we can use this code:</p> <h2>example.h</h2> <pre><code>#ifndef EXAMPLE_H #define EXAMPLE_H class Math { public: int pi() const { return this-&gt;_pi; } void pi(int pi) { this-&gt;_pi = pi; } private: int _pi; }; #endif </code></pre> <h2>example.i</h2> <pre><code>%module example %{ #define SWIG_FILE_WITH_INIT #include "example.h" %} [essentially example.h repeated again] </code></pre> <h2>example.cpp</h2> <pre><code>#include "example.h" </code></pre> <h2>util.py</h2> <pre><code>class PropertyVoodoo(type): """A metaclass. Initializes when the *class* is initialized, not the object. Therefore, we are free to muck around the class methods and, specifically, descriptors.""" def __init__(cls, *a): # OK, so the list of C++ properties using the style described # in the OP is stored in a __properties__ magic variable on # the class. for prop in cls.__properties__: # Get accessor. def fget(self): # Get the SWIG class using super. We have to use super # because the only information we're working off of is # the class object itself (cls). This is not the most # robust way of doing things but works when the SWIG # class is the only superclass. s = super(cls, self) # Now get the C++ method and call its operator(). return getattr(s, prop)() # Set accessor. def fset(self, value): # Same as above. s = super(cls, self) # Call its overloaded operator(int value) to set it. return getattr(s, prop)(value) # Properties in Python are descriptors, which are in turn # static variables on the class. So, here we create the # static variable and set it to the property. setattr(cls, prop, property(fget=fget, fset=fset)) # type() needs the additional arguments we didn't use to do # inheritance. (Parent classes are passed in as arguments as # part of the metaclass protocol.) Usually a = [&lt;some swig # class&gt;] right now. super(PropertyVoodoo, cls).__init__(*a) # One more piece of work: SWIG selfishly overrides # __setattr__. Normal Python classes use object.__setattr__, # so that's what we use here. It's not really important whose # __setattr__ we use as long as we skip the SWIG class in the # inheritance chain because SWIG's __setattr__ will skip the # property we just created. def __setattr__(self, name, value): # Only do this for the properties listed. if name in cls.__properties__: object.__setattr__(self, name, value) else: # Same as above. s = super(cls, self) s.__setattr__(name, value) # Note that __setattr__ is supposed to be an instance method, # hence the self. Simply assigning it to the class attribute # will ensure it's an instance method; that is, it will *not* # turn into a static/classmethod magically. cls.__setattr__ = __setattr__ </code></pre> <h2>somefile.py</h2> <pre><code>import example from util import PropertyVoodoo class Math(example.Math): __properties__ = ['pi'] __metaclass__ = PropertyVoodoo m = Math() print m.pi m.pi = 1024 print m.pi m.pi = 10000 print m.pi </code></pre> <p>So the end result is just that you have to create a wrapper class for every SWIG Python class and then type two lines: one to mark which methods should be converted in properties and one to bring in the metaclass.</p>
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    1. COThis looks like it should do the trick! It is a shame SWIG doesn't have a more direct mechanism for making properties.
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    2. COIs there any declaration syntax that it will recognize as a property? getPropName/setPropName maybe?
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    3. COIt doesn't look like SWIG tries to generate those, although I only spent about an hour or so with SWIG documentation in writing the code for this answer and it's entirely possible there's a way I haven't come across.
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