ENH: add a comments variable to pandas.DataFrame.to_csv #59839
Description
Feature Type
-
Adding new functionality to pandas
-
Changing existing functionality in pandas
-
Removing existing functionality in pandas
Problem Description
For many years I have been adding comments to my Pandas generated CSV files by pre--generating the header, writing out the comments, and then appending the pandas to_csv output:
df = ....
with open('example.csv', mode='w') as f:
f.write(','.join(df.keys())+'\n')
f.write('# First comment\n')
f.write('# Second comment...\n')
df.to_csv('example.csv', mode='a', index=False)
see StackOverflow post for examples: https://stackoverflow.com/questions/29233496/write-comments-in-csv-file-with-pandas
I think it would be easy to add a "comments" variable to to_csv to write out a list of comments in the header prepended with whatever the comment character is set:
my_comments = ["First comment",
"Second comment..."]
df.to_csv('example.csv', comments=my_comments, index=False)
and it would produce a CSV similar to:
Var1, Var2
# First comment
# Second comment...
123, 456
I think this would be an easy add, and I am willing to code it up and make a pull request, but would like to see if there is any buy-in before spending the time.
Feature Description
It would be nice if pandas to_csv had a comments variable that worked something like:
my_comments = ["First comment",
"Second comment..."]
df.to_csv('example.csv', comments=my_comments, index=False)
and it would produce a CSV similar to:
Var1, Var2
# First comment
# Second comment...
123, 456
Alternative Solutions
For years I have been adding comments to my Pandas generated CSV files by doing something like:
df = ....
with open('example.csv', mode='w') as f:
f.write(','.join(df.keys())+'\n')
f.write('# First comment\n')
f.write('# Second comment...\n')
df.to_csv('example.csv', mode='a', index=False)
see StackOverflow post for examples: https://stackoverflow.com/questions/29233496/write-comments-in-csv-file-with-pandas
Additional Context
People have been using workarounds for a decade or more (see: https://stackoverflow.com/questions/29233496/write-comments-in-csv-file-with-pandas ), and it would be much more elegant if Pandas added the ability to inject comments into a CSV header.