word_count_in_file.py

from collections import Counter

cnt = Counter()

print('start')
with open('input.txt') as f:
    for line in f:
        splits = line.split(' - ', 1)
        if len(splits) > 1:
            cnt[splits[1]] += 1

with open('output.txt', 'w') as wf:
    for k, v in cnt.most_common():
        wf.write( "{} {}\n".format(k,v) )

print('done')