ValueError:关闭文件的I/O操作

Question

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)

这里,p是一本字典,w并且c都是字符串.

当我尝试在文件中写入时,它报告错误:

ValueError : I/O operation on closed file.

帮助我,我是python的新手.我正在使用Python 2.7.3提前谢谢你.

Answer 1

缩进正确; for声明应该在内部with块:

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)

在with块外,文件已关闭.

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

Answer 2

混合使用：制表符+空格会引起相同的错误。

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