wc.py

wc.py

import sys
import re

def count_word(lines):
    words = {}
    sum = 0
    for line in lines:
        line = re.sub(r'\r\n|\n|\.|,|-|\"|\'|\[|\]|_|\*|:|\;|\(|\)|\/|\&|!|\?', ' ', line).lower()
        n = line.split()
        sum += len(n)
        for word in n:
            if word in words:
                words[word] += 1
            else:
                words[word] = 1
    return sorted(words.items(), key = lambda w: w[1], reverse = True), sum

argc = len(sys.argv)
if argc == 1:
    lines = sys.stdin.readlines()
    wcs, sum = count_word(lines)
elif argc == 2:
    try:
        f = open(sys.argv[1], 'rU')
        lines = f.readlines()
        wcs, sum = count_word(lines)
        f.close()
    except IOError:
        print("Error: open file", sys.stderr)
        sys.exit(1)
else:
    sys.exit('usage: wc [file]')

print('Number of words: {0}'.format(sum))
print('Top 20 frequent words:')
for wc in wcs[:20]:
    print(wc)