20.7. httplib — HTTP protocol client

This module defines classes which implement the client side of the HTTP and HTTPS protocols. It is normally not used directly — the module urllib uses it to handle URLs that use HTTP and HTTPS.

The module provides the following classes:

class httplib.HTTPConnection(host[, port[, strict[, timeout[, source_address]]]])

An HTTPConnection instance represents one transaction with an HTTP server. It should be instantiated passing it a host and optional port number. If no port number is passed, the port is extracted from the host string if it has the form host:port, else the default HTTP port (80) is used. When True, the optional parameter strict (which defaults to a false value) causes BadStatusLine to be raised if the status line can’t be parsed as a valid HTTP/1.0 or 1.1 status line. If the optional timeout parameter is given, blocking operations (like connection attempts) will timeout after that many seconds (if it is not given, the global default timeout setting is used). The optional source_address parameter may be a tuple of a (host, port) to use as the source address the HTTP connection is made from.

For example, the following calls all create instances that connect to the server at the same host and port:

>>> h1 = httplib.HTTPConnection('www.cwi.nl')
>>> h2 = httplib.HTTPConnection('www.cwi.nl:80')
>>> h3 = httplib.HTTPConnection('www.cwi.nl', 80)
>>> h3 = httplib.HTTPConnection('www.cwi.nl', 80, timeout=10)

New in version 2.0.

Changed in version 2.6: timeout was added.

Changed in version 2.7: source_address was added.

class httplib.HTTPSConnection(host[, port[, key_file[, cert_file[, strict[, timeout[, source_address]]]]]])

A subclass of HTTPConnection that uses SSL for communication with secure servers. Default port is 443. key_file is the name of a PEM formatted file that contains your private key. cert_file is a PEM formatted certificate chain file.

Note

This does not do any certificate verification.

New in version 2.0.

Changed in version 2.6: timeout was added.

Changed in version 2.7: source_address was added.

class httplib.HTTPResponse(sock[, debuglevel=0][, strict=0])

Class whose instances are returned upon successful connection. Not instantiated directly by user.

New in version 2.0.

class httplib.HTTPMessage

An HTTPMessage instance is used to hold the headers from an HTTP response. It is implemented using the mimetools.Message class and provides utility functions to deal with HTTP Headers. It is not directly instantiated by the users.

The following exceptions are raised as appropriate:

exception httplib.HTTPException

The base class of the other exceptions in this module. It is a subclass of Exception.

New in version 2.0.

exception httplib.NotConnected

A subclass of HTTPException.

New in version 2.0.

exception httplib.InvalidURL

A subclass of HTTPException, raised if a port is given and is either non-numeric or empty.

New in version 2.3.

exception httplib.UnknownProtocol

A subclass of HTTPException.

New in version 2.0.

exception httplib.UnknownTransferEncoding

A subclass of HTTPException.

New in version 2.0.

exception httplib.UnimplementedFileMode

A subclass of HTTPException.

New in version 2.0.

exception httplib.IncompleteRead

A subclass of HTTPException.

New in version 2.0.

exception httplib.ImproperConnectionState

A subclass of HTTPException.

New in version 2.0.

exception httplib.CannotSendRequest

A subclass of ImproperConnectionState.

New in version 2.0.

exception httplib.CannotSendHeader

A subclass of ImproperConnectionState.

New in version 2.0.

exception httplib.ResponseNotReady

A subclass of ImproperConnectionState.

New in version 2.0.

exception httplib.BadStatusLine

A subclass of HTTPException. Raised if a server responds with a HTTP status code that we don’t understand.

New in version 2.0.

The constants defined in this module are:

httplib.HTTP_PORT

The default port for the HTTP protocol (always 80).

httplib.HTTPS_PORT

The default port for the HTTPS protocol (always 443).

and also the following constants for integer status codes:

httplib.responses

This dictionary maps the HTTP 1.1 status codes to the W3C names.

Example: httplib.responses[httplib.NOT_FOUND] is 'Not Found'.

New in version 2.5.

>>> import httplib
>>> conn = httplib.HTTPConnection("www.python.org")
>>> conn.request("GET", "/index.html")
>>> r1 = conn.getresponse()
>>> print r1.status, r1.reason
200 OK
>>> data1 = r1.read()
>>> conn.request("GET", "/parrot.spam")
>>> r2 = conn.getresponse()
>>> print r2.status, r2.reason
404 Not Found
>>> data2 = r2.read()
>>> conn.close()

>>> import httplib
>>> conn = httplib.HTTPConnection("www.python.org")
>>> conn.request("HEAD","/index.html")
>>> res = conn.getresponse()
>>> print res.status, res.reason
200 OK
>>> data = res.read()
>>> print len(data)
0
>>> data == ''
True

>>> import httplib, urllib
>>> params = urllib.urlencode({'spam': 1, 'eggs': 2, 'bacon': 0})
>>> headers = {"Content-type": "application/x-www-form-urlencoded",
...            "Accept": "text/plain"}
>>> conn = httplib.HTTPConnection("musi-cal.mojam.com:80")
>>> conn.request("POST", "/cgi-bin/query", params, headers)
>>> response = conn.getresponse()
>>> print response.status, response.reason
200 OK
>>> data = response.read()
>>> conn.close()