python 修改文件内容函数

import os
def change_file(address,line,content):
    #修改文件指定行
    f=open(address,"r",encoding="utf-8")
    f2=open("temporary_file.txt","w",encoding="utf-8")
    i=0
    for v in f:
        i+=1
        if i==line:
            f2.write(content)
        else:
            f2.write(v)
    f.close()
    f2.close()
    f = open(address, "w" ,encoding="utf-8")
    f2=open("temporary_file.txt", "r",encoding="utf-8")
    for v in f2:
        f.write(v)
    f.close()
    f2.close()
change_file("yesterday.txt",1,"ols li\n")
def file_replace(address,find_str,replace_str,replacenum=1):
    #替换文件指定词,默认替换一次，
    with open(address,"r",encoding="utf-8") as f,          open("temporary_file.txt", "w", encoding="utf-8") as f2:
         if replacenum <=0:
              return 0
         else:
              for v in f:
                   if replacenum == 0:
                        f2.write(v)
                   else:
                        if replacenum <= v.count(find_str):
                             f2.write(v.replace(find_str, replace_str, replacenum))
                             replacenum = 0
                        else:
                             f2.write(v.replace(find_str, replace_str))
                        replacenum = replacenum - v.count(find_str)
    f = open(address, "w" ,encoding="utf-8")
    f2=open("temporary_file.txt", "r",encoding="utf-8")
    for v in f2:
        f.write(v)
    f.close()
    f2.close()
file_replace("yesterday.txt","昨日","今天",2)