11.5.2 OpenerDirector Objects

OpenerDirector instances have the following methods:

add_handler( handler)

handler should be an instance of BaseHandler. The following methods are searched, and added to the possible chains.

protocol_open() -- signal that the handler knows how to open protocol URLs.
protocol_error_type() -- signal that the handler knows how to handle type errors from protocol.

close( ): Explicitly break cycles, and delete all the handlers. Because the OpenerDirector needs to know the registered handlers, and a handler needs to know who the OpenerDirector who called it is, there is a reference cycle. Even though recent versions of Python have cycle-collection, it is sometimes preferable to explicitly break the cycles.

open( url[, data]): Open the given url (which can be a request object or a string), optionally passing the given data. Arguments, return values and exceptions raised are the same as those of urlopen() (which simply calls the open() method on the default installed OpenerDirector).

error( proto[, arg[, ...]]): Handle an error in a given protocol. This will call the registered error handlers for the given protocol with the given arguments (which are protocol specific). The HTTP protocol is a special case which uses the HTTP response code to determine the specific error handler; refer to the http_error_*() methods of the handler classes.
Return values and exceptions raised are the same as those of urlopen().

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