Another (more concise, more Pythonic) frequency word counter using collections.Counter.

word_counter.py

 # collections.Counter docs at:
 # https://docs.python.org/3/library/collections.html#collections.Counter

from collections import Counter
import re

with open("txt_file.txt", "r") as f:
    words = re.findall(r"\w+", f.read().lower())
  
totals = Counter(words).most_common(50) # returns a list of tuples for the 50 most common words and their counts

for word in totals:
    print(word[0], "=", word[1])