ValueError : I/O operation on closed file

--------------------------------------------------
Rise to the top 3% as a developer or hire one of them at Toptal: https://topt.al/25cXVn
--------------------------------------------------

Music by Eric Matyas
https://www.soundimage.org
Track title: Digital Sunset Looping

--

Chapters
00:00 Valueerror : I/O Operation On Closed File
00:23 Accepted Answer Score 231
00:43 Answer 2 Score 11
00:55 Answer 3 Score 0
01:07 Answer 4 Score 0
01:21 Thank you

--

Full question
https://stackoverflow.com/questions/1895...

--

Content licensed under CC BY-SA
https://meta.stackexchange.com/help/lice...

--

Tags
#python #csv #fileio #io

#avk47

ACCEPTED ANSWER

Score 231

Indent correctly; your for statement should be inside the with 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)

Outside the with block, the file is closed.

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

ANSWER 2

Score 11

Same error can raise by mixing: tabs + spaces.

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

ANSWER 3

Score 0

file = open("filename.txt", newline='')
for row in self.data:
    print(row)

Save data to a variable(file), so you need a with.

ANSWER 4

Score 0

I had this problem when I was using an undefined variable inside the with open(...) as f:. I removed (or I defined outside) the undefined variable and the problem disappeared.