How can 2 Python dictionaries become 1?

The "oneliner way", altering neither of the input dicts, is

basket = dict(basket_one, **basket_two)

In case of conflict, the items from basket_two will override the ones from basket_one. As one-liners go, this is pretty readable and transparent, and I have no compunction against using it any time a dict that's a mix of two others comes in handy (any reader who has trouble understanding it will in fact be very well served by the way this prompts him or hear towards learning about dict and the ** form;-). So, for example, uses like:

x = mungesomedict(dict(adict, **anotherdict))

are reasonably frequent occurrences in my code.

Note: In Python 3, this will only work if every key in anotherdict is a string. See these alternatives.

basket = basket_one.copy()
basket.update(basket_two)

(if the original basket_one does not need to stay intact, you can leave out the copy)