综合练习：词频统计

f = open("F:geci.txt","r")
lrc = f.read()
f.close()
a = (''',.?-''')
for i in a:
lrc = lrc.replace(i," ")
lrc = lrc.lower()
lrc = lrc.split()
d = set(lrc)
di = {}
for i in d:
    di[i] = lrc.count(i)
print(di)
prep = {'of','a'}
for i in prep:
    del(di[i])
dic1 = sorted(di.items(),key=lambda d:d[1],reverse= True)
print(dic1)

for i in range(20):
    print(dic1[i])