class attribute on the subclass. (Contributed by Jason R Coombs in
:issue:`18978`.)
+:class:`~urllib.request.Request` objects are now reusable: if the
+:attr:`~urllib.request.Request.full_url` or :attr:`~urllib.request.Request.data`
+attributes are modified, all relevant internal properties are updated. This
+means, for example, that it is now possible to use the same
+:class:`~urllib.request.Request` object in more than one
+:meth:`.OpenerDirector.open` call with different *data* arguments, or to
+modify a :class:`~urllib.request.Request`\ 's ``url`` rather than recomputing it
+from scratch. There is also a new
+:meth:`~urllib.request.Request.remove_header` method that can be used to remove
+headers from a :class:`~urllib.request.Request`. (Contributed by Alexey
+Kachayev in :issue:`16464`, Daniel Wozniak in :issue:`17485`, and Damien Brecht
+and Senthil Kumaran in :issue:`17272`.)
+
unittest
--------
to procedurally generate, in an easy way, small test instances.
- Issue #17485: Also delete the Request Content-Length header if the data
- attribute is deleted. (Follow on to issue 16464).
+ attribute is deleted. (Follow on to issue Issue #16464).
- Issue #15927: CVS now correctly parses escaped newlines and carriage
when parsing with quoting turned off.
list() calls aren't added to filter(), map(), and zip() which are directly
passed enumerate().
+- Issue #16464: Reset the Content-Length header when a urllib Request is reused
+ with new data.
+
- Issue #12848: The pure Python pickle implementation now treats object
lengths as unsigned 32-bit integers, like the C implementation does.
Patch by Serhiy Storchaka.