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pythonpandasdataframeargskeyword-argument

Apply function to multiple pandas columns with Args


I wrote the following function:

def unique_values(df, column):

unique = df[column].unique()
clean = pd.DataFrame.from_dict(unique)
clean.columns = [column]

return clean

I would like to apply the following function to various columns in a df. As something like this:

unique1, unique2, unique3 = unique_values(df, "Column1", "Column2", "Column3")

If I add an args in the following way:

 def unique_values(df, *column):

    unique = df[column].unique()
    clean = pd.DataFrame.from_dict(unique)
    clean.columns = [column]

    return clean

and apply the function like this:

 unique1, unique2, unique3 = unique_values(df, "Column1", "Column2", "Column3")

I get the following error:

KeyError: ('Column1', 'Column2', 'Column3')

Any help would be appreciated


Solution

  • You can do it this way by iterating though column:

    def unique_values(df, *column):
        to_return=[]
        for col in column:
            unique = df[col].unique()
            clean = pd.DataFrame.from_dict(unique)
            clean.columns = [col]
            to_return.append(clean)
        return to_return
    # this way this works:
    unique1, unique2, unique3 = unique_values(df, "Column1", "Column2", "Column3")