第 0006 题：你有一个目录，放了你一个月的日记，都是 txt，为了避免分词的问题，假设内容都是英文，请统计出你认为每篇日记最重要的词。

import os

os.chdir('C:/workspace')

def count_words(inputname):
fh=open(inputname)
read_fh=fh.read()
fh.close()
number=1
is_alpha=[]
dict_words={}
ignore_words=['a','an','is','it','are','of','by','the','and','for','in','to']

for word in read_fh:#取出文本中的非英文字符
if word.isalpha():
is_alpha.append(word)
elif word=='\t' or word=='\n' or word==' ':
is_alpha.append(word)
fh_alpha=''.join(is_alpha)
fh_words=fh_alpha.split()
for words in fh_words: #建立单词及频次的字典
words=words.lower()
if words not in dict_words and words not in ignore_words:
dict_words[words]=number
elif words in ignore_words:
continue
else:
dict_words[words]=dict_words[words]+1
#字典按值排序
dict_sort= sorted(dict_words.iteritems(), key=lambda d:d[1], reverse = True)

print 'Maximum number of words is "%s" and it appear "%d" times'%(dict_sort[0][0],dict_sort[0][1])
print 'Second number of words is "%s" and it appear "%d" times'%(dict_sort[1][0],dict_sort[1][1])
print 'Third number of words is "%s" and it appear "%d" times'%(dict_sort[2][0],dict_sort[2][1])

count_words("words.txt")