Replace None with NaN in pandas dataframe

You can use DataFrame.fillna or Series.fillna which will replace the Python object None, not the string 'None'.

import pandas as pdimport numpy as np

For dataframe:

df = df.fillna(value=np.nan)

For column or series:

df.mycol.fillna(value=np.nan, inplace=True)

pandas dataframe replace nan nonetype

The following line replaces None with NaN:

df['column'].replace('None', np.nan, inplace=True)

pandas dataframe replace nan nonetype

Here's another option:

df.replace(to_replace=[None], value=np.nan, inplace=True)

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