英文词频统计

# news='''A special variant of the Code Completion " 
#      "feature invoked by pressing Ctrl twice " 
#      "allows you to complete the name of any class no matter " 
#      "if it was imported in the current file or not. If the class " 
#      "is not imported yet, the import statement is generated automatically.'''
f=open('news.txt','r')
news=f.read()
f.close()
sep=''',.?'":!'''
exclude={'the','and','a','not'}
for c in sep:
    news=news.replace(c,' ')

wordList=news.lower().split()
wordDict={}
'''for w in wordList:
    wordDict[w]=wordDict.get(w,0)+1
    for w in exclude
     del(wordDict[w])
 '''
wordSet=set(wordList)-exclude
for w in wordSet:
    wordDict[w]=wordList.count(w)

dictList=list(wordDict.items())
dictList.sort(key=lambda x:x[1],reverse=True)
# for w in wordDict:
#     print(w,wordDict[w])
#print(dictList)

for i in range(20):
    print(dictList[i])