all Python 3urllib.requestfunction

urllib.request.build_opener()

openers

Builds an OpenerDirector from the standard handlers plus yours — the way to set up proxies, cookies, authentication and headers.

Syntax

opener = urllib.request.build_opener(handler, ...)

A handler you pass replaces the standard one of the same class or a subclass instead of sitting next to it; you may pass a class, and it is created without arguments. ProxyHandler joins only when *_proxy variables are set, so the same program talks to the network differently on different machines; ProxyHandler({}) turns proxies off explicitly. The result affects only opener.open() — urlopen() does not know about it without install_opener().

Examples

import urllib.request
opener = urllib.request.build_opener(urllib.request.ProxyHandler({}))
names = [type(h).__name__ for h in opener.handlers]
print('ProxyHandler' in names, 'DataHandler' in names)  # → False True
print(opener.open('data:,hi').read())  # → b'hi'
print(opener.addheaders)  # → ? [('User-agent', 'Python-urllib/3.14')]

See also

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