def _put_conn(self, conn):
        try:
            self.pool.put(conn, block=False)
            return  # Everything is dandy, done.
        except AttributeError:
            # self.pool is None.
            pass
        except Full:
            # This should never happen if self.block == True
            log.warning(
                "Connection pool is full, discarding connection: %s",
                self.host)

        # Connection never got put back into the pool, close it.
        if conn:
            conn.close()
Put a connection back into the pool.
dataset/ETHPy150Open kennethreitz/requests/requests/packages/urllib3/connectionpool.py/HTTPConnectionPool._put_conn