# pandas.DataFrame.combine_first

`DataFrame.``combine_first`(other)

  Combine two DataFrame objects and default to non-null values in frame calling the method. Result index columns will be the union of the respective indexes and columns

  Parameters: | other : DataFrame
  Returns: | combined : DataFrame

  Examples

  a’s values prioritized, use values from b to fill holes:

      >>> a.combine_first(b)