Sorting lists by only using the numbers in the value

Question

let's say i have this list

a = ['20 - A', '200 - A', '30 - B']

and i want to sort it in a way that will sort by the numbers like so:

['20 - A', '30 - B', '200 - A']

i know i can split the values by finding the first space but i can't think of a way to sort it after i do

Answer 1

>>> a = ['20 - A', '200 - A', '30 - B']
>>> sorted(a, key = lambda x: int(x.split()[0]))

>>> ['20 - A', '30 - B', '200 - A']