Python - app to count a number of words

Question

I have to create a program to count the number of words from a text file.

So, my plan:

-user enters name of txt file,

-app load it into variable 'text',

-make it lowercase,

-search only words without signs like '/''#' and no whitespace etc. only alpha string

-make it into a list of words,

-show all the words, 1st should have the biggest number of uses, the last should be used at least 1 time

How to change that to include words only with minimum length +3? Example: in, on, at <- should not include list, word, appear, clear <- should be included.

from collections import Counter
import re


def open_file():
    file_name = input("Enter a filename: ")  # enter name of file which should be open
    with open(file_name) as f:  # it should exist in project folder
        text = f.read()  # load file into var text
    f.close()  # close the file
    return text

try:
    text = open_file()  # open file and write it into var
    except FileNotFoundError:
        print("File was not found!")
        text = "" # if FileNotFoundError = True -> text = none

    lower_text = text.lower()  # transform txt into lower cases
    text_with_out_special_signs = re.findall(r'[a-z]*', lower_text)  #delete signs like =,#,!

    counts_of_words = Counter(text_with_out_special_signs)  # transform list in Counter

    for x in counts_of_words.most_common():  # show results
        print(x)

Answer 1

If you want to remove words with less than 3 characters you could do something like this:

text_more_than_3_char_words = [w for w in text_with_out_special_signs if len(w) > 2]
counts_of_words = Counter(text_more_than_3_char_words)  # transform list in Counter