I have a dataframe with nans in it:
>>>df.head() Out[1]: JPM US SMALLER COMPANIES C ACC 1990-01-02 NaN 1990
You have two options:
1) Specific for each column
cols_fillna = ['column1','column2','column3'] # replace 'NaN' with zero in these columns for col in cols_fillna: df[col].fillna(0,inplace=True) df[col].fillna(0,inplace=True)
2) For the entire dataframe
df = df.fillna(0)