2_-1.py

import argparse
from operator import itemgetter
import sys

parser=argparse.ArgumentParser()
parser.add_argument('file', help='name of the file', type=str)
parser.add_argument('-n', help='number of words',type = int)
parser.add_argument('-s', help='short words',action = 'store_true')
options=parser.parse_args()

f = open(options.file, 'r')
dict = {}
text = f.read()
text = text.replace(',',' ')
text = text.replace('.', ' ')
text = text.split()

for i in range(len(text)):
    dict[text[i]] = dict.get(text[i],0) + 1
a=sorted(dict.items(), key=lambda x:x[1], reverse=True)
#a=sorted(dict.items(), key=itemgetter(1), reverse=True)
if options.s:
    a = [(x,y) for x,y in a if len(x)>2]
    a = a[:options.n]
else:
    a = a[:options.n]

for k,v in a:
    if options.s:
        if len(k) > 2:
            print k, v, "%.4f" % (float(v) / len(text))
    else:
        print k, v, float(v) / len(text)