Replace None with NaN in pandas dataframe

The following line replaces None with NaN:

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

Here's another option:

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

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

import pandas as pd
import numpy as np

For dataframe:

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

For column or series:

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

Related