python统计单词出现的次数

#统计单词出现次数
import re
with open("实验三\word.txt",'r',encoding='utf-8') as f:
    str=f.read()
print(str)
#去英文标点
# for i in str:
#     if i in string.punctuation:
#         str = str.replace(i," ")
# print(str)
lis=re.findall(r'\b\w+\b',str)
# lis.remove(lis[3])
# print(lis)

randon = "ssssssssssssssssssssssssss"
# print(lis)

"""
版权所有
"""

dic = {}
while(len(lis)):
    check = lis.pop()
    if(check != randon):
        times = 1
        for x in range (len(lis)):
            if(check == lis[x]):
                times = times + 1
                lis[x] = randon
        dic[check] = times

print(dic)

错误想法

# dic={}
# newlis=[]
# i=0    
# while(i<len(lis)):
#     count=1
#     for j in range(i+1,len(lis)):
#         if(lis[i]==lis[j]):
#             count=count+1
#             newlis.append(j)
 
#     dic[lis[i]]=count
#     i=i+1
#     for j in range(len(newlis)):
#         if(i==newlis[j]):
#             i=i+1



#错误原因：假设newlis[4,3,5,7],i=3时i+1=4无法遍历回去