DOC: Typo(s?) in pandas.DataFrame.isin

[loucadufault]

• 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/pandas-docs/stable/reference/api/pandas.DataFrame.isin.html

Documentation problem

In the last example, the text introducing the code snippet reads:

When values is a Series or DataFrame the index and column must match. Note that ‘falcon’ does not match based on the number of legs in df2.

However, "df2" does not exist in the included code snippet (it is instead called "other").

Additionally, I am not comfortable enough with pandas to assert this, but it seems like the text should incorrectly states that "falcon" does not match, since "falcon" indeed does match for both columns, see the relevant portion of the code snippet:

>>> df.isin(other)
        num_legs  num_wings
falcon      True       True
dog        False      False

Suggested fix for documentation

Text should at least read:

When values is a Series or DataFrame the index and column must match. Note that ‘falcon’ does not match based on the number of legs in other.

or the variable in the code snippet should be renamed to "df2".

Additionally, something may need to be done to address the potential discrepancy in saying that "falcon" does not match.

[Varun270]

@loucadufault I am not able to find out the exact location of the file that needs to be fixed. Can you tell me what is the location of this file? I tried finding it through this link https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.DataFrame.isin.html but wasn't able to spot the relevant folders.

[johnzangwill]

@Varun270 The file is frame.py. If you want to fix it I'll leave it to you. Otherwise, I can.

[MarcoGorelli]

@loucadufault I am not able to find out the exact location of the file that needs to be fixed. Can you tell me what is the location of this file? I tried finding it through this link https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.DataFrame.isin.html but wasn't able to spot the relevant folders.

You can find locations clicking on 'source':

[Varun270]

@Varun270 The file is frame.py. If you want to fix it I'll leave it to you. Otherwise, I can.

Yeah, I would love to fix this issue. Thanks !!!

[Varun270]

take

[Varun270]

[Varun270]

[Varun270]

@MarcoGorelli I have pushed the changes but somehow instead of pushing it from Development ----> Master. I pushed it from Development ----> Development. Development is a branch that I made. what should I do now to fix this delete the previous commit and again create a PR?

[MarcoGorelli]

you can make a new branch - I recommend the first 3 chapters of this book for getting familiar with the git workflow

[johnzangwill]

@Varun270 Just follow the "contributing" instructions to the letter. Yes, there is a bit of a learning curve...

I suggest that you change your change slightly. You say "Note that 'falcon' does not match based on the number of legs in other."
But in fact it does match.

I would change to:

other = pd.DataFrame({'num_legs': [8, 3], 'num_wings': [0, 2]},index=['spider', 'falcon'])

Then you will indeed get the falcon not matching:

 >>> df.isin(other)
                num_legs  num_wings
        falcon     False       True
        dog        False      False