python - Why don't list operations return the resulting list?

Question

I'm interested in the thought process that led to this. To me, a relative newbie, it seems hampering, since it prevents "chaining" of list processing (e.g. mylist.reverse().append('a string')[:someLimit]). I imagine it might be that "The Powers That Be" decided that list comprehension is a better paradigm (a valid opinion), and so didn't want to encourage other methods - but it seems perverse to prevent an intuitive method, even if better alternatives exist.

Note that I'm not complaining (I'm sure there is a sensible reason, I'm just interested in what it is!), nor looking for a solution (the comments here were very instructive) - just looking for some context, and a deeper understanding of the language's design process.

Answer 1

The general design principle in Python is for functions that mutate an object in-place to return None. I'm not sure it would have been the design choice I'd have chosen, but it's basically to emphasise that a new object is not returned.

(GvR's (our Python BDFL) states the design choice here: http://mail.python.org/pipermail/python-dev/2003-October/038855.html)