Greg Wilson writes:
Should we then add dict.push(), which would add a key/value pair to the dictionary? I realize it's redundant (same effect as 'dict[x] = y'),
We don't have .push(), and I don't think the metaphor really works well with dictionaries. There's also an implied ordering relationship between push() and pop(), and this doesn't hold for dictionaries either.
but I think anyone who's gone through a CS course in data structures and algorithms will expect push() where there's pop(), and it will allow functions to be polymorphic over lists and dicts.
There's only a limited amount on conceptual polymorphism between the two; artificial extending that may lead to a lot of programmers using the wrong structure for their application.