*headers* should be a dictionary, and will be treated as if
:meth:`add_header` was called with each key and value as arguments.
- This is often used to "spoof" the ``User-Agent`` header, which is
+ This is often used to "spoof" the ``User-Agent`` header value, which is
used by a browser to identify itself -- some HTTP servers only
allow requests coming from common browsers as opposed to scripts.
For example, Mozilla Firefox may identify itself as ``"Mozilla/5.0
Examples
--------
+In addition to the examples below, more examples are given in
+:ref:`urllib-howto`.
+
This example gets the python.org main page and displays the first 300 bytes of
it. ::
import urllib.request
req = urllib.request.Request('http://www.example.com/')
req.add_header('Referer', 'http://www.python.org/')
+ # Customize the default User-Agent header value:
+ req.add_header('User-Agent', 'urllib-example/0.1 (Contact: . . .)')
r = urllib.request.urlopen(req)
:class:`OpenerDirector` automatically adds a :mailheader:`User-Agent` header to