def load_pip_requirements(self, files_map=None, freeze=True):
        if files_map is None:
            files_map = self.default_pip_files
        for group, requirements_txt in files_map.items():
            path = Path(requirements_txt)
            if not path.exists() and group.lower() == "all" and freeze:
                cmd = envoy.run("pip freeze")
                self[group].loads(cmd.std_out)
            elif path.exists():
                self[group].load(path)
def _from_python(self, key, value):
        new_path = self._path + (key,)
        if isinstance(value, dict):
            value = self.custom_classes.get(new_path, ConfigDict)(value, new_path)
        elif isinstance(value, list):
            value = self.custom_classes.get(new_path, ConfigList)(value, new_path)
        elif isinstance(value, str):
            match = self.PROXY_VAR_RE.match(value)
            if match:
                value = self._make_proxy(key, match)
        return value