Counting frequency of string or float in a list

Question

I have a list. Its pretty big. It has over 1 million entries. I want to count the frequency of each string in it. It stores numbers as strings from 1 to 1000. I have used the following but it keeps running for hours:

d = {b:a.count(b) for b in a}
n, m = d.keys(), d.values()
print n, m

Answer 1

Use collections.Counter instead:

from collections import Counter
d = Counter(a)

n, m = d.keys(), d.values()
print n, m