Suggestion: make sequence and map interfaces more similar

[Random832]

On Tue, Mar 29, 2016, at 20:56, Chris Angelico wrote:
> The map contract is this:
> 
> x = StrangeDict()
> x[123] = 456
> ...
> assert x[123] == 456
> 
> Your mapping does violate the map contract.

So, you can put *anything* in that "..."?

x = dict()
x[123] = 456
x[123] = 789
assert x[123] == 456

dict violates the map contract.