doctest support for cython

cydoctest.py

#!/usr/bin/env python
"""
Cython-compatible wrapper for doctest.testmod().

Usage example, assuming a Cython module mymod.pyx is compiled.
This is run from the command line, passing a command to Python:
python -c "import cydoctest, mymod; cydoctest.testmod(mymod)"

(This still won't let a Cython module run its own doctests
when called with "python mymod.py", but it's pretty close.
Further options can be passed to testmod() as desired, e.g. 
verbose=True.)

http://wiki.cython.org/FAQ#HowcanIrundoctestsinCythoncode.28pyxfiles.29.3F

Changed to support (with pyximport):

    $ python -mcydoctest mymod.pyx
"""
try:
    import pyximport; pyximport.install()
except ImportError:
    pass # ignore
import doctest
import inspect
import os
import sys

def _from_module(module, object):
    """
    Return true if the given object is defined in the given module.
    """
    if module is None:
        return True
    elif inspect.getmodule(object) is not None:
        return module is inspect.getmodule(object)
    elif inspect.isfunction(object):
        return module.__dict__ is object.func_globals
    elif inspect.isclass(object):
        return module.__name__ == object.__module__
    elif hasattr(object, '__module__'):
        return module.__name__ == object.__module__
    elif isinstance(object, property):
        return True # [XX] no way not be sure.
    else:
        raise ValueError("object must be a class or function")

def fix_module_doctest(module):
    """
    Extract docstrings from cython functions, that would be skipped by doctest
    otherwise.
    """
    module.__test__ = {}
    for name in dir(module):
       value = getattr(module, name)
       if inspect.isbuiltin(value) and isinstance(value.__doc__, str) and _from_module(module, value):
           module.__test__[name] = value.__doc__

def testmod(m=None, *args, **kwargs):
    """
    Fix a Cython module's doctests, then call doctest.testmod()
    
    All other arguments are passed directly to doctest.testmod().
    """
    fix_module_doctest(m)
    return doctest.testmod(m, *args, **kwargs)

def _test():
    """adapted from stdlib's doctest.py"""
    testfiles = [arg for arg in sys.argv[1:] if arg and arg[0] != '-']
    if not testfiles:
        name = os.path.basename(sys.argv[0])
        if '__loader__' in globals():          # python -m
            name, _ = os.path.splitext(name)
        print("usage: {0} [-v] file ...".format(name))
        return 2
    for filename in testfiles:
        if filename.endswith((".py", ".pyx")):
            # It is a module -- insert its dir into sys.path and try to
            # import it. If it is part of a package, that possibly
            # won't work because of package imports.
            dirname, filename = os.path.split(filename)
            sys.path.insert(0, dirname)
            _, ext = os.path.splitext(filename)
            m = __import__(filename[:-len(ext)])
            del sys.path[0]
            failures, _ = testmod(m)
        else:
            failures, _ = doctest.testfile(filename, module_relative=False)
        if failures:
            return 1
    return 0


if __name__ == "__main__":
    sys.exit(_test())