Httpx

Changed

* Preserve HTTP header casing. (Pull 1338, encode/httpcore216, python-hyper/h11104)
* Drop `response.next()` and `response.anext()` methods in favour of `response.next_request` attribute. (Pull 1339)
* Closed clients now raise a runtime error if attempting to send a request. (Pull 1346)

Added

* Add Python 3.9 to officially supported versions.
* Type annotate `__enter__`/`__exit__`/`__aenter__`/`__aexit__` in a way that supports subclasses of `Client` and `AsyncClient`. (Pull 1336)

Added

* Add `response.next_request` (Pull 1334)

Added

* Support direct comparisons between `Headers` and dicts or lists of two-tuples. Eg. `assert response.headers == {"Content-Length": 24}` (Pull 1326)

Fixed

* Fix automatic `.read()` when `Response` instances are created with `content=<str>` (Pull 1324)

Fixed

* Fixed connection leak in async client due to improper closing of response streams. (Pull 1316)

Fixed

* Fixed `response.elapsed` property. (Pull 1313)
* Fixed client authentication interaction with `.stream()`. (Pull 1312)

Fixed

* ASGITransport now properly applies URL decoding to the `path` component, as-per the ASGI spec. (Pull 1307)