capybara/virtualenv/lib/python2.7/site-packages/setuptools/extension.py
def _convert_pyx_sources_to_lang(self):
        """
        Replace sources with .pyx extensions to sources with the target
        language extension. This mechanism allows language authors to supply
        pre-converted sources but to prefer the .pyx sources.
        """
        if have_pyrex():
            # the build has Cython, so allow it to compile the .pyx files
            return
        lang = self.language or ''
        target_ext = '.cpp' if lang.lower() == 'c++' else '.c'
        sub = functools.partial(re.sub, '.pyx$', target_ext)
        self.sources = list(map(sub, self.sources))
def _convert_pyx_sources_to_lang(self):
        if have_pyrex():
            # the build has Cython, so allow it to compile the .pyx files
            return
        lang = self.language or ''
        target_ext = '.cpp' if lang.lower() == 'c++' else '.c'
        sub = functools.partial(re.sub, '.pyx$', target_ext)
        self.sources = list(map(sub, self.sources))
def _convert_pyx_sources_to_lang ( self ) : if have_pyrex ( ) : # the build has Cython, so allow it to compile the .pyx files return lang = self . language or '' target_ext = '.cpp' if lang . lower ( ) == 'c++' else '.c' sub = functools . partial ( re . sub , '.pyx$' , target_ext ) self . sources = list ( map ( sub , self . sources ) )
Replace sources with .pyx extensions to sources with the target
        language extension. This mechanism allows language authors to supply
        pre-converted sources but to prefer the .pyx sources.
Replace sources with . pyx extensions to sources with the target language extension . This mechanism allows language authors to supply pre - converted sources but to prefer the . pyx sources .