文本内容替换

实现简单的文本内容修改

f = open("yesterday",'r',encoding='utf-8')
f_new = open('new_yesterday','w',encoding='utf-8')

old_content = input("输入要修改的内容：")
new_content = input("输入要改为的内容：")
for line in f:
    if old_content in line:
        line = line.replace(old_content,new_content)
    f_new.write(line)

f.close()
f_new.close()