# 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

  See also

  `DataFrame.combine`
    Perform series-wise operation on two DataFrames using a given function

  Examples

  df1’s values prioritized, use values from df2 to fill holes:

      >>> df1 = pd.DataFrame([[1, np.nan]])
      >>> df2 = pd.DataFrame([[3, 4]])
      >>> df1.combine_first(df2)
         0    1
      0  1  4.0

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