Class PoolManager

src/urllib3/poolmanager.py:162–503

Allows for arbitrary requests while transparently keeping track of necessary connection pools for you. :param num_pools: Number of connection pools to cache before discarding the least recently used pool. :param headers: Headers to include with all requests

class PoolManager(RequestMethods):
    """
    Allows for arbitrary requests while transparently keeping track of
    necessary connection pools for you.

    :param num_pools:
        Number of connection pools to cache before discarding the least
        recently used pool.

    :param headers:
        Headers to include with all requests, unless other headers are given
        explicitly.

    :param \\**connection_pool_kw:
        Additional parameters are used to create fresh
        :class:`urllib3.connectionpool.ConnectionPool` instances.

    Example:

    .. code-block:: python

        import urllib3

        http = urllib3.PoolManager(num_pools=2)

        resp1 = http.request("GET", "https://google.com/")
        resp2 = http.request("GET", "https://google.com/mail")
        resp3 = http.request("GET", "https://yahoo.com/")

        print(len(http.pools))
        # 2

    """

    proxy: Url | None = None
    proxy_config: ProxyConfig | None = None

    def __init__(
        self,
        num_pools: int = 10,
        headers: typing.Mapping[str, str] | None = None,
        **connection_pool_kw: typing.Any,
    ) -> None:
        super().__init__(headers)
        # PoolManager handles redirects itself in PoolManager.urlopen().
        # It always passes redirect=False to the underlying connection pool to
        # suppress per-pool redirect handling. If the user supplied a non-Retry
        # value (int/bool/etc) for retries and we let the pool normalize it
        # while redirect=False, the resulting Retry object would have redirect
        # handling disabled, which can interfere with PoolManager's own
        # redirect logic. Normalize here so redirects remain governed solely by
        # PoolManager logic.
        if "retries" in connection_pool_kw:
            retries = connection_pool_kw["retries"]
            if not isinstance(retries, Retry):
                retries = Retry.from_int(retries)
                connection_pool_kw = connection_pool_kw.copy()
                connection_pool_kw["retries"] = retries