Example script using a Counter to count occurancies of all words in a given text file

count-words-of-textfile.py

from collections import Counter

# Change the path to whatever file you want to be read 
pth = 'MOBY-DICK.txt'

with open(pth) as f:
    words = f.read().lower().split()
    ct = Counter(words)
    
print (ct.most_common(100))
print (ct['in,']) # just splitting on spaces will produce strings that have non-alphabetic characters at the beginning or end (like 'in,' or "'the")


# target = '-wordCount.'.join(pth.rsplit('.', 1))
# with open(target, 'w') as f:
#    f.write('\n'.join([f'{k}: {v}'  for k,v in ct.most_common()]))

To remove the strings with non alphabetic characters a line of regex could help.
There are two examples
– include only alphabetic character
– exclude some non alphabetic characters

from collections import Counter
import re 


pth = 'MOBY-DICK.txt'

with open(pth) as f:
    # choose one of the two lines below 
    txt = re.sub(r'[^a-zA-Z\s]+', ' ', f.read().lower()) # this will also remove the æ in vertebræ (8 occurancies). 
    txt = re.sub(r'[\.\,\(\)\'\"\;”\“\—\!\?\:]+', ' ', f.read().lower()) # this might not find all non-alphabetic charcters. 
    words = txt.split()
    ct = Counter(words)
    
print (ct.most_common(100))
print (ct['in,'])