Use slice notation on URI's for authentication creds

[ptmcg]

While on the topic of operator overloading on the SO Python chat, I got the idea after chatting with @amcgregor that adding a slice notation to a URI would be a nice extension of this embedded DSL syntax:

Example:

url = URI["username":"password"]

This would be easy and intuitive in interactive sessions, without extra API namespace clutter.

[amcgregor]

Experimenting in a REPL, I was dubious about the use of colon notation, however, apparently, slice() is a honey-badger and doesn't care that the "indexes" are non-numeric. Yay!

class Foo:
	def __getitem__(self, item): return item

Foo()["username":"password"].start == "username"

[amcgregor]

In the process of implementing, use of slices this way will return a new URI instance and will not mutate the original. Isolation of this behaviour to slices preserves existing mapping behaviour of URIs to their query string components.

[amcgregor]

Feature merged. Will be present in next release. As a note, the next release will be the final release supporting Python 2.