Check if a series exists in dataframe

Question

I need to check if a series already exists as a row in the dataframe. The dataframe is as follows-

 Name Age University 0 Ankit NaN BHU 1 Aishwarya 21.0 JNU 2 Shaurya 22.0 DU

I have tried-

(df == ser).all(1).any()

It works fine when the dataframe and series do not have null values. For example, if the series is ['Aishwarya', 21.0, 'JNU'], the output is True, which is correct. However, if the series is ['Ankit', np.nan, 'BHU'], the output is False, even if the series exists in the dataframe.

Minimum, reproducible example for my problem-

details = {'Name':['Ankit', 'Aishwarya', 'Shaurya'], 'Age':[np.nan, 21, 22], 'University':['BHU', 'JNU', 'DU']} df = pd.DataFrame(details, columns = ['Name', 'Age', 'University']) ser1 = pd.Series(['Ankit', np.nan, 'BHU'], index = ['Name', 'Age', 'University']) ser2 = pd.Series(['Aishwarya', 21.0, 'JNU'], index = ['Name', 'Age', 'University']) print((ser1 == df).all(1).any()) print((ser2 == df).all(1).any())

Actual Output-

False True

Expected Output-

True True

jlb_gouveia · Accepted Answer · 2020-11-06 12:11:30Z

3

By definition np.nan == np.nan is False

Try using df.isin() instead:

df.isin([*ser1]).all(1).any() True

edited Nov 6, 2020 at 12:11

answered Nov 5, 2020 at 22:21

jlb_gouveia

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2 Comments

Shradha Over a year ago

This returns False.

jlb_gouveia Over a year ago

Hi @Shradha, changed it. I was originally testing with lists instead of series. Turning the series into a list already works out

Shradha · Accepted Answer · 2021-01-26 20:40:41Z

Found an answer here as well.

print(ser1.astype(str).eq(df.astype(str)).all(1).any()) # True print(ser2.astype(str).eq(df.astype(str)).all(1).any()) # True

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