一、修改原文件方式
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")
二、把原文件内容和要修改的内容写到新文件中进行存储的方式
import osdef 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:
forlinein f1:
ifold_strin 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")
2.2 python 使用正则表达式 替换文件内容 re.sub 方法替换
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")
