Connection Pools¶
-
class
urllib3.
HTTPConnectionPool
(host, port=None, strict=False, timeout=<object object>, maxsize=1, block=False, headers=None, retries=None, _proxy=None, _proxy_headers=None, **conn_kw)¶ Bases:
urllib3.connectionpool.ConnectionPool
,urllib3.request.RequestMethods
Thread-safe connection pool for one host.
- Parameters
host – Host used for this HTTP Connection (e.g. “localhost”), passed into
httplib.HTTPConnection
.port – Port used for this HTTP Connection (None is equivalent to 80), passed into
httplib.HTTPConnection
.strict –
Causes BadStatusLine to be raised if the status line can’t be parsed as a valid HTTP/1.0 or 1.1 status line, passed into
httplib.HTTPConnection
.Note
Only works in Python 2. This parameter is ignored in Python 3.
timeout – Socket timeout in seconds for each individual connection. This can be a float or integer, which sets the timeout for the HTTP request, or an instance of
urllib3.util.Timeout
which gives you more fine-grained control over request timeouts. After the constructor has been parsed, this is always a urllib3.util.Timeout object.maxsize – Number of connections to save that can be reused. More than 1 is useful in multithreaded situations. If
block
is set to False, more connections will be created but they will not be saved once they’ve been used.block – If set to True, no more than
maxsize
connections will be used at a time. When no free connections are available, the call will block until a connection has been released. This is a useful side effect for particular multithreaded situations where one does not want to use more than maxsize connections per host to prevent flooding.headers – Headers to include with all requests, unless other headers are given explicitly.
retries – Retry configuration to use by default with requests in this pool.
_proxy – Parsed proxy URL, should not be used directly, instead, see
urllib3.connectionpool.ProxyManager
”_proxy_headers – A dictionary with proxy headers, should not be used directly, instead, see
urllib3.connectionpool.ProxyManager
”**conn_kw – Additional parameters are used to create fresh
urllib3.connection.HTTPConnection
,urllib3.connection.HTTPSConnection
instances.
-
ConnectionCls
¶ alias of
urllib3.connection.HTTPConnection
-
ResponseCls
¶ alias of
urllib3.response.HTTPResponse
-
close
()¶ Close all pooled connections and disable the pool.
-
is_same_host
(url)¶ Check if the given
url
is a member of the same host as this connection pool.
-
scheme
= 'http'¶
-
urlopen
(method, url, body=None, headers=None, retries=None, redirect=True, assert_same_host=True, timeout=<object object>, pool_timeout=None, release_conn=None, chunked=False, body_pos=None, **response_kw)¶ Get a connection from the pool and perform an HTTP request. This is the lowest level call for making a request, so you’ll need to specify all the raw details.
Note
More commonly, it’s appropriate to use a convenience method provided by
RequestMethods
, such asrequest()
.Note
release_conn will only behave as expected if preload_content=False because we want to make preload_content=False the default behaviour someday soon without breaking backwards compatibility.
- Parameters
method – HTTP request method (such as GET, POST, PUT, etc.)
body – Data to send in the request body (useful for creating POST requests, see HTTPConnectionPool.post_url for more convenience).
headers – Dictionary of custom headers to send, such as User-Agent, If-None-Match, etc. If None, pool headers are used. If provided, these headers completely replace any pool-specific headers.
retries (
Retry
, False, or an int.) –Configure the number of retries to allow before raising a
MaxRetryError
exception.Pass
None
to retry until you receive a response. Pass aRetry
object for fine-grained control over different types of retries. Pass an integer number to retry connection errors that many times, but no other types of errors. Pass zero to never retry.If
False
, then retries are disabled and any exception is raised immediately. Also, instead of raising a MaxRetryError on redirects, the redirect response will be returned.redirect – If True, automatically handle redirects (status codes 301, 302, 303, 307, 308). Each redirect counts as a retry. Disabling retries will disable redirect, too.
assert_same_host – If
True
, will make sure that the host of the pool requests is consistent else will raise HostChangedError. When False, you can use the pool on an HTTP proxy and request foreign hosts.timeout – If specified, overrides the default timeout for this one request. It may be a float (in seconds) or an instance of
urllib3.util.Timeout
.pool_timeout – If set and the pool is set to block=True, then this method will block for
pool_timeout
seconds and raise EmptyPoolError if no connection is available within the time period.release_conn – If False, then the urlopen call will not release the connection back into the pool once a response is received (but will release if you read the entire contents of the response such as when preload_content=True). This is useful if you’re not preloading the response’s content immediately. You will need to call
r.release_conn()
on the responser
to return the connection back into the pool. If None, it takes the value ofresponse_kw.get('preload_content', True)
.chunked – If True, urllib3 will send the body using chunked transfer encoding. Otherwise, urllib3 will send the body using the standard content-length form. Defaults to False.
body_pos (int) – Position to seek to in file-like body in the event of a retry or redirect. Typically this won’t need to be set because urllib3 will auto-populate the value when needed.
**response_kw – Additional parameters are passed to
urllib3.response.HTTPResponse.from_httplib()
-
class
urllib3.
HTTPSConnectionPool
(host, port=None, strict=False, timeout=<object object>, maxsize=1, block=False, headers=None, retries=None, _proxy=None, _proxy_headers=None, key_file=None, cert_file=None, cert_reqs=None, key_password=None, ca_certs=None, ssl_version=None, assert_hostname=None, assert_fingerprint=None, ca_cert_dir=None, **conn_kw)¶ Bases:
urllib3.connectionpool.HTTPConnectionPool
Same as
HTTPConnectionPool
, but HTTPS.When Python is compiled with the
ssl
module, thenVerifiedHTTPSConnection
is used, which can verify certificates, instead ofHTTPSConnection
.VerifiedHTTPSConnection
uses one ofassert_fingerprint
,assert_hostname
andhost
in this order to verify connections. Ifassert_hostname
is False, no verification is done.The
key_file
,cert_file
,cert_reqs
,ca_certs
,ca_cert_dir
,ssl_version
,key_password
are only used ifssl
is available and are fed intourllib3.util.ssl_wrap_socket()
to upgrade the connection socket into an SSL socket.-
ConnectionCls
¶ alias of
urllib3.connection.HTTPSConnection
-
scheme
= 'https'¶
-
-
class
urllib3.connectionpool.
ConnectionPool
(host, port=None)¶ Bases:
object
Base class for all connection pools, such as
HTTPConnectionPool
andHTTPSConnectionPool
.Note
ConnectionPool.urlopen() does not normalize or percent-encode target URIs which is useful if your target server doesn’t support percent-encoded target URIs.
-
QueueCls
¶ alias of
urllib3.util.queue.LifoQueue
-
close
()¶ Close all pooled connections and disable the pool.
-
scheme
= None¶
-