转载自 cnblogs python修改文件内容3种方法
修改原文件
def alter(file,old_str,new_str):
# 替换文件中的字符串
# :param file:文件名
# :param old_str:就字符串
# :param new_str:新字符串
# :return:
file_data = ""
with open(file, "r", encoding="utf-8") as f:
for line in f:
if old_str in line:
line = line.replace(old_str,new_str)
file_data += line
with open(file,"w",encoding="utf-8") as f:
f.write(file_data)
alter("file1", "09876", "python")
写新文件
字符串替换
import os
def alter(file,old_str,new_str):
# 将替换的字符串写到一个新的文件中，然后将原文件删除，新文件改为原来文件的名字
# :param file: 文件路径
# :param old_str: 需要替换的字符串
# :param new_str: 替换的字符串
# :return: None
with open(file, "r", encoding="utf-8") as f1,open("%s.bak" % file, "w", encoding="utf-8") as f2:
for line in f1:
if old_str in line:
line = line.replace(old_str, new_str)
f2.write(line)
os.remove(file)
os.rename("%s.bak" % file, file)
alter("file1", "python", "测试")
正则表达替换
import re,os
def alter(file,old_str,new_str):
with open(file, "r", encoding="utf-8") as f1,
open("%s.bak" % file, "w", encoding="utf-8") as f2:
for line in f1:
f2.write(re.sub(old_str,new_str,line))
os.remove(file)
os.rename("%s.bak" % file, file)
alter("file1", "admin", "password")
