ValueError:对已关闭文件的I/O操作

import csv    

with open('v.csv', 'w') as csvfile:
     cwriter = csv.writer(csvfile, delimiter=' ', quotechar='|', quoting=csv.QUOTE_MINIMAL)

for w, c in p.iteritems():
    cwriter.writerow(w + c)

Here, p is a dictionary, w and c both are strings.

这里p是字典，w和c都是字符串。

When I try to write in the file it reports error:

当我试图写入文件时，它会报告错误:

ValueError : I/O operation on closed file.

Help me, I'm really new to python. I'm working with Python 2.7.3 Thank you in advance.

帮帮我，我对python很陌生。我正在使用Python 2.7.3，提前谢谢。

2 个解决方案

#1

Indent correctly; for statement should be inside with block:

正确的缩进;对于语句应该在block中:

import csv    

with open('v.csv', 'w') as csvfile:
    cwriter = csv.writer(csvfile, delimiter=' ', quotechar='|', quoting=csv.QUOTE_MINIMAL)

    for w, c in p.iteritems():
        cwriter.writerow(w + c)

Outside the with block, the file is closed.

在带有块的外部，文件被关闭。

>>> with open('/tmp/1', 'w') as f:
...     print f.closed
... 
False
>>> print f.closed
True

#2

Same error can raise by mixing: tabs + spaces.

同样的错误可以通过混合:制表符+空格来增加。

with open('/foo', 'w') as f:
 (spaces OR  tab) print f       <-- success
 (spaces AND tab) print f       <-- fail

#1