python統計文本中的單詞數和print的兩種寫法

#!/usr/bin/python
# - * - coding: utf-8 - * -
#做用，分別計算每一個文本的單詞數，而且輸出全部文本的單詞總數
a = []
sum = 0
def count_words(filename):
#filename = '1.txt'
 try:
  with open(filename) as file_object:
   t = file_object.read()
 except IOError:
  print 'you have' + ' ' + filename + ' is not exist!'
 else:
  words = t.split()
  numbers = len(words)
  a.append(numbers)
    #print的兩種寫法，能夠帶逗號，後面直接跟參數值。也能夠不帶逗號，後面直接跟%參數值
  print 'danci de geshi yigong shi %d'  %numbers
#    #print 'danci de geshi yigong shi' , numbers

filenames = [ '1.txt','2.txt','3.txt' ]
for filename in filenames:
 count_words(filename)

for i in a:
 sum += int(i)
print sum
#兩種寫法，一個是用sum計數，一個用sum函數，
#sum的參數是一個list，這裏a就是list
#print '全部單詞總數爲' + str(sum(a))