problem_34.py

'''
Statement:
======================
Write a procedure char_freq_table() that, when run in a terminal,
accepts a file name from the user,
builds a frequency listing of the characters contained in the file,
and prints a sorted and nicely formatted character frequency table
to the screen.
'''
import re
#filename = input("Enter filename: ")
filename = "words.txt"
fin = open(filename,"r")
all_lines = fin.readlines()
char_dict = dict()
for line in all_lines:
    line = line[:-1]
    words = line.split(" ")
    for word in words:
        word = re.sub("[^a-zA-Z]+", "", word)
        for c in word:
            if c in char_dict:
                char_dict[c]=char_dict[c]+1
            else:
                char_dict[c]=1

sorted_char_dict = sorted(char_dict, key=char_dict.get, reverse=True)
                
for c in sorted_char_dict:
    print(c," ",char_dict[c])