0.18.0 (27th April, 2021)

The 0.18.x release series formalises our low-level Transport API, introducing the base classes httpx.BaseTransport and httpx.AsyncBaseTransport.

See the "Writing custom transports" documentation and the httpx.BaseTransport.handle_request() docstring for more complete details on implementing custom transports.

Pull request #1522 includes a checklist of differences from the previous httpcore transport API, for developers implementing custom transports.

The following API changes have been issuing deprecation warnings since 0.17.0 onwards, and are now fully deprecated...

• You should now use httpx.codes consistently instead of httpx.StatusCodes.
• Use limits=... instead of pool_limits=....
• Use proxies={"http://": ...} instead of proxies={"http": ...} for scheme-specific mounting.

Changed

• Transport instances now inherit from httpx.BaseTransport or httpx.AsyncBaseTransport, and should implement either the handle_request method or handle_async_request method. (Pull #1522, #1550)
• The response.ext property and Response(ext=...) argument are now named extensions. (Pull #1522)
• The recommendation to not use data=<bytes|str|bytes (a)iterator> in favour of content=<bytes|str|bytes (a)iterator> has now been escalated to a deprecation warning. (Pull #1573)
• Drop Response(on_close=...) from API, since it was a bit of leaking implementation detail. (Pull #1572)
• When using a client instance, cookies should always be set on the client, rather than on a per-request basis. We prefer enforcing a stricter API here because it provides clearer expectations around cookie persistence, particularly when redirects occur. (Pull #1574)
• The runtime exception httpx.ResponseClosed is now named httpx.StreamClosed. (#1584)
• The httpx.QueryParams model now presents an immutable interface. The is a discussion on the design and motivation here. Use client.params = client.params.merge(...) instead of client.params.update(...). The basic query manipulation methods are query.set(...), query.add(...), and query.remove(). (#1600)

Added

• The Request and Response classes can now be serialized using pickle. (#1579)
• Handle data={"key": [None|int|float|bool]} cases. (Pull #1539)
• Support httpx.URL(**kwargs), for example httpx.URL(scheme="https", host="www.example.com", path="/'), or httpx.URL("https://www.example.com/", username="tom@gmail.com", password="123 456"). (Pull #1601)
• Support url.copy_with(params=...). (Pull #1601)
• Add url.params parameter, returning an immutable QueryParams instance. (Pull #1601)
• Support query manipulation methods on the URL class. These are url.copy_set_param(), url.copy_add_param(), url.copy_remove_param(), url.copy_merge_params(). (Pull #1601)
• The httpx.URL class now performs port normalization, so :80 ports are stripped from http URLs and :443 ports are stripped from https URLs. (Pull #1603)
• The URL.host property returns unicode strings for internationalized domain names. The URL.raw_host property returns byte strings with IDNA escaping applied. (Pull #1590)

Fixed

• Fix Content-Length for cases of files=... where unicode string is used as the file content. (Pull #1537)
• Fix some cases of merging relative URLs against Client(base_url=...). (Pull #1532)
• The request.content attribute is now always available except for streaming content, which requires an explicit .read(). (Pull #1583)