req_install.py 文件源码

def build_location(self, build_dir):
        if self._temp_build_dir is not None:
            return self._temp_build_dir
        if self.req is None:
            # for requirement via a path to a directory: the name of the
            # package is not available yet so we create a temp directory
            # Once run_egg_info will have run, we'll be able
            # to fix it via _correct_build_location
            self._temp_build_dir = tempfile.mkdtemp('-build', 'pip-')
            self._ideal_build_dir = build_dir
            return self._temp_build_dir
        if self.editable:
            name = self.name.lower()
        else:
            name = self.name
        # FIXME: Is there a better place to create the build_dir? (hg and bzr
        # need this)
        if not os.path.exists(build_dir):
            logger.debug('Creating directory %s', build_dir)
            _make_build_dir(build_dir)
        return os.path.join(build_dir, name)