Python ValueError：已关闭文件的 I/O 操作。示例教程不起作用
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Python ValueError: I/O operation on closed file. sample tutorial not working
提问by Riaz Ladhani
I am following a tutorial to learn to read and write to a file. I am getting the following error. I do not understand why.
我正在按照教程学习读写文件。我收到以下错误。我不理解为什么。
C:\Python27\python.exe "C:/Automation/Python/Write to files/test3.py"
Traceback (most recent call last):
File "C:/Automation/Python/Write to files/test3.py", line 8, in <module>
f.read('newfile.txt', 'r')
ValueError: I/O operation on closed file
My code is
我的代码是
f = open("newfile.txt", "w")
f.write("hello world\n")
f.write("Another line\n")
f.close()
f.read('newfile.txt', 'r')
print f.read()
I have tried to put f.closeat the bottom of the code but I still get the same error.
我试图放在f.close代码的底部，但我仍然遇到同样的错误。
The write part works if I comment out the f.read. It is failing on the f.readpart.
如果我注释掉f.read. 它在这方面失败了f.read。
采纳答案by Bhargav Rao
The line after f.close()that is f.read('newfile.txt', 'r')should be f = open('newfile.txt', 'r').
后该生产线f.close()是f.read('newfile.txt', 'r')应该f = open('newfile.txt', 'r')。
That is
那是
f = open('newfile.txt', 'r')
print f.read()
f.close()
After which you need to add f.close()again.
之后您需要f.close()再次添加。
Small Note
小笔记
As in Python, the default value for 2nd arg of openis r, you can simple do open('newfile.txt')
在 Python 中，第二个参数的默认值open是r，你可以简单地做open('newfile.txt')
回答by paul100
As illustrated above when you closed the file you need to open your file so that you can read it
如上图所示，当您关闭文件时，您需要打开文件才能阅读它
f = open('newfile.txt', 'r')
print f.read()
f.close()
回答by Rishabh
You can't perform I/O operation on file_obj after closing it i.e.
关闭 file_obj 后不能对它执行 I/O 操作，即
file_obj.close()
So if you want to open the same file do:
因此，如果您想打开相同的文件，请执行以下操作：
if(file_obj.closed):
file_obj = open(file_obj.name, file_obj.mode)
print (file.obj.read())
file_obj.close()
