DOC: Typo in `fillna()` documentation

[cesare-spinoso]

• I have checked that the issue still exists on the latest versions of the docs on master here

Location of the documentation

https://pandas.pydata.org/docs/reference/api/pandas.DataFrame.fillna.html

Documentation problem

Typo in one of the examples for fillna(). Specifically, the last example with df2 = pd.DataFrame(np.zeros((4, 4)), columns=list("ABCE")) where the last column should be E but is instead D in the printout.

Suggested fix for documentation

Either fix to df2 = pd.DataFrame(np.zeros((4, 4)), columns=list("ABCD")) or fix the printout.

[MarcoGorelli]

I believe this is intentional, to show that you can fill with a DataFrame which has extra columns not present in the original one

[mzeitlin11]

Thanks for noting this @cesare-spinoso. I think this is not explicitly wrong - since column "E" does not match any column in df1, that column is essentially just ignored - and column "D" in df1 is unaffected.

However, since there are no missing values in column "D" in df1, this example could probably be improved to show it more explicitly

[mzeitlin11]

whoops sorry @MarcoGorelli just saw your comment

[cesare-spinoso]

Aha! Makes sense, maybe it's just me but that was easy to miss. Perhaps an extra line explaining just that could be useful? I'll leave it up to you.

[mzeitlin11]

Yeah I think an extra line could help - or adding a missing value to column "D" to make it more obvious that it is not being filled

[erfannariman]

take