Python in a Nutshell

Name

urlopen

Synopsis

urlopen(urlstring,data=None)

Accesses the given URL and returns a read-only file-like object f. f supplies file-like methods read, readline, readlines, and close, as well as two others:

f .geturl( )

Returns the URL of f. This may differ from urlstring both because of normalization (as mentioned for function urlunsplit earlier) and because the server may issue HTTP redirects (i.e., indications that the requested data is located elsewhere). urllib supports redirects transparently, and method geturl lets you check for them if you want.

f .info( )

Returns an instance m of class Message of module mimetools, covered in Chapter 21. The main use of m is as a container of headers holding metadata about f. For example, m ['Content-Type'] is the MIME type and subtype of the data in f. You can also access this information by calling m’s methods m .gettype( ), m .getmaintype( ), and m .getsubtype( ).

When data is None and urlstring’s scheme is http, urlopen sends a GET request. When data is not None, urlstring’s scheme must be http, and urlopen sends a POST request. data must then be in URL-encoded form, and you normally prepare it with function urlencode, covered earlier in this section.

urlopen can transparently use proxies that do not require authentication. Set environment variables http_proxy, ftp_proxy, and gopher_proxy to the proxies’ URLs to exploit this. You normally perform such settings in your system’s environment, in platform-dependent ways, before ...