'打开（）'不起作用？

Question

我的代码：

filename = "C:/users/patrik/documents/mypython.txt" 
with open(filename) as f: 
    if f.readlines()[0] == "patrik's file": #first line 
     f.write("This file has been read by patrik!") 

为什么它不工作？我没有收到任何错误，此后文件内容变得杂乱，我做错了什么？

Answer 1

要执行读取和写文件操作就可以选择这些模式之一：

'r+'：

Opens a file for both reading and writing. The file pointer will be at the beginning of the file.

'a+'：

Opens a file for both appending and reading. The file pointer is at the end of the file if the file exists. The file opens in the append mode. If the file does not exist, it creates a new file for reading and writing.

注意file是一个内嵌函数在python中，所以你不应该用它作为变量名称