keyring/credentials.py
def _get_env(self, env_var):
        """Helper to read an environment variable
        """
        value = os.environ.get(env_var)
        if not value:
            raise ValueError('Missing environment variable:%s' % env_var)
        return value
def _get_env(self, env_var):
        """Helper to read an environment variable
        """
        value = os.environ.get(env_var)
        if not value:
            raise ValueError('Missing environment variable:%s' % env_var)
        return value
Helper to read an environment variable