def load_installed_version(self):
        installed_packages = get_installed_pypackages()
        if self.package in installed_packages:
            self.version = "=={}".format(
                installed_packages[self.package].version)
def _invert_results(self, candidates):
        inverted_candidates = list(self.directory)

        for candidate in candidates:
            try:
                inverted_candidates.remove(candidate)
            except ValueError:
                pass

        return inverted_candidates