文件方式实现完整的英文词频统计实例

1. 读入待分析的字符串
2. 分解提取单词 
3. 计数字典
4. 排除语法型词汇
5. 排序
6. 输出TOP(20)

fo=open('test.txt','w')
>>> fo.write('''Twinkle Twinkle Little Star
　　(Declan's Prayer) - Declan Galbraith

　　Twinkle twinkle little star,
　　How I wonder what you are,
　　Up above the world so high,
　　Like a diamond in the sky,
　　Star light,
　　Star bright,
　　The first star I see tonight,
　　I wish I may, I wish I might,
　　Have the wish I wish tonight,

　　Twinkle twinkle little star,
　　How I wonder what you are,
　　I have so many wishes to make,
　　But most of all is what I state,
　　So just wonder,
　　That I've been dreaming of,
　　I wish that I can have owe her enough,
　　I wish I may, I wish I might,
　　Have the dream I dream tonight,

　　Ooo baby

　　Twinkle twinkle little star,
　　How I wonder what you are,
　　I want a girl who'll be all mine,
　　And wants to say that I'm her guy,
　　Someone's sweet that's for sure,
　　I want to be the one shes looking for,
　　I wish I may, I wish I might,
　　Have the girl I wish tonight,

　　Ooo baby

　　Twinkle twinkle little star,
　　How I wonder what you are,
　　Up above the world so high,
　　Like a diamond in the sky,
　　Star light,
　　Star bright,
　　The first star I see tonight,
　　I wish I may, I wish I might,
　　Have the wish I wish tonight.''')
1138
>>> fo.close()
>>> fr=open('test.txt','r')
>>> fr.read()

fo=open('test.txt','r')
song=fo.read()
exc={'the','in','to','a','of','and','on','what','that'}
song=song.lower()
for i in '''.,-
	u3000'()"''':
    song=song.replace(i,'')
words=song.split(' ')
dic={}
keys=set(words)
keys=keys-exc
for w in keys:
    dic[w]=words.count(w)

wc = list(dic.items())
wc.sort(key=lambda x:x[1],reverse=True)
print(wc)
for w in range(20):
    print(wc[w])