There was a bug introduced in #18676 which caused fast-path deletes
implemented as "DELETE WHERE pk IN <subquery>" to fail if the SELECT
clause contained additional stuff (for example extra() and annotate()).

Thanks to Trac alias pressureman for spotting this regression.

Thanks mrmachine for the review.

This case was originally designed to handle Exception's which didn't gracefully support coercing themselves to unicode. However, because it lives in the `else` case of `if hasattr(s, '__unicode__'):` we can be sure it's no longer reachable in djanog anymore, because since Python 2.5 exception has subclassed object, which means Exception objects always have an __unicode__ method.

response.content can be accessed many times as desired, and always
returns the same result.

iter(response) works only once and consumes the iterator.

in HttpResponses instantiated with iterators.

Thanks maxirobaina for the report.

Thanks vlinhart for the report and Łukasz Rekucki for the patch.

Thanks Mario César for the report and draft patch.

This commit caused every test that does two or more assertContains to
fail, because of #6527. It also made HttpResponse non-pickleable.

Refs #13222.

Fixed #19162 -- Wrong indentation.

Thanks teepark for the report and grahamd for his insights.

Thanks Alexey Boriskin for the report. Refs #18240.

Iterators will be closed for both regular and streaming responses;
this shouldn't be described as a difference.

Refs #7581. Thanks mrmachine.

Cleaned up the the http module. Moved all of the code from __init__.py to request.py, response.py and utils.py

Fixed #19142 -- Language codes can include numbers (RFC 3066)

removing typo in the process. Thanks to Carlos Palol for the catch.
Closes pull 450

Allow reversed iteration over SortedDict.

Fixed #19151 -- Added missing methods to EmptyQuerySet.

Added values() and values_list() methods to EmptyQuerySet.

Fixed #13869 - Warned that QuerySet.iterator() doesn't affect DB driver caching; thanks jtiai for the suggestion.

Thanks mrmachine and everyone else involved on this long-standing ticket.

Thanks ybon, quinode and sjaensch for the patch, and Tim Graham
for the review.

Thanks Ondrej Slinták for the suggestion.

Thanks paulegan for the report and Preston Holmes for the review.

We probably historically customized it for good reasons, but
currently, the differences with upstream Python are not
significant any longer.
Also fixes #19075 for which a test has been added.