pandas.DataFrame.combine
- 
DataFrame.combine(other, func, fill_value=None, overwrite=True)[source]
- 
Add two DataFrame objects and do not propagate NaN values, so if for a (column, time) one frame is missing a value, it will default to the other frame’s value (which might be NaN as well) Parameters: other : DataFrame func : function fill_value : scalar value overwrite : boolean, default True If True then overwrite values for common keys in the calling frame Returns: result : DataFrame 
    © 2008–2012, AQR Capital Management, LLC, Lambda Foundry, Inc. and PyData Development Team
Licensed under the 3-clause BSD License.
    https://pandas.pydata.org/pandas-docs/version/0.20.3/generated/pandas.DataFrame.combine.html