Count & Sort occurrences of text in a file

[buran]

That's GREAT, but how can I sort the final list according to the number of occurrences?

you can use most_common() method of Counter:

Return a list of the n most common elements and their counts from the most common to the least. If n is omitted or None, most_common() returns all elements in the counter. Elements with equal counts are ordered in the order first encountered:

from collections import Counter
  
with open('dupes.csv', "r") as f:
    for name, name_count in Counter(f).most_common():
        print(f'{name.strip()}:{name_count}')