python - 值错误 : I/O operation on closed file

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.items():
    cwriter.writerow(w + c)

这里，p是字典，w和c都是字符串。

当我尝试写入文件时，它会报告错误:

ValueError: I/O operation on closed file.

Answer 1

正确缩进；您的 for 语句应该在 with 内 block :

import csv    

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

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

在 with block 之外，文件被关闭。

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