Write newline to csv in Python

Question

I want to end each interation of a for loop with writing a new line of content (including newline) to a csv file. I have this:

# Set up an output csv file with column headers
with open('outfile.csv','w') as f:
    f.write("title; post")
    f.write("\n")

This does not appear to write an actual \n (newline) the file. Further:

    # Concatenate into a row to write to the output csv file
    csv_line = topic_title + ";" + thread_post
    with open('outfile.csv','w') as outfile:
                 outfile.write(csv_line + "\n")

This, also, does not move the cursor in the outfile to the next line. Each new line, with every iteration of the loop, just overwrites the most recent one.

I also tried outfile.write(os.linesep) but did not work.

score 20 · Accepted Answer · answered May 02 '17 at 08:19

20

change 'w' to 'a'

with open('outfile.csv','a')

answered May 02 '17 at 08:19

fuwiak

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Why would this work ? Can you explain how changing the access modifier alters the EOL character? Why wouldn't write('\n') work ? – Sean Munson Aug 19 '19 at 18:15
1

I think OP is opening/closing the file within a loop (they mention a loop but don't show where it is), so opening in append mode is a "fix", but is *the wrong way*. – Nick T Jan 03 '20 at 21:15
Yes, that's a workaround, not a solution. – sjantke Jan 25 '21 at 14:11

score 5 · Answer 2 · answered May 02 '17 at 08:21

5

with open('outfile.csv', 'w', newline='') as f:
    f.writerow(...)

Alternatively:

f = csv.writer('outfile.csv', lineterminator='\n')

answered May 02 '17 at 08:21

Chankey Pathak

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score 1 · Answer 3 · answered Mar 24 '19 at 08:54

1

I confront with same problem， only need follow:

  f = csv.writer('outfile.csv', lineterminator='\n')

answered Mar 24 '19 at 08:54

Lee Ran

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score 1 · Answer 4 · edited Jun 24 '21 at 18:46

1

If your using python2 then use

with open('xxx.csv', 'a') as f:
    writer = csv.writer(f)
    writer.writerow(fields)

If you are using python3 make use of newline=''

edited Jun 24 '21 at 18:46

crodev

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answered Jun 24 '21 at 12:41

Prashant

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score 0 · Answer 5 · edited Jul 12 '21 at 07:00

0

Please try with: open(output_file_name.csv, 'a+', newline='') as f:

edited Jul 12 '21 at 07:00

Toto Briac

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answered Jul 12 '21 at 04:43

e.amin

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Write newline to csv in Python

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