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# pandas.DataFrame.map

DataFrame.map(func, na_action=None, **kwargs)

  Apply a function to a Dataframe elementwise.

  Added in version 2.1.0: DataFrame.applymap was deprecated and renamed to DataFrame.map.

  This method applies a function that accepts and returns a scalar to every element of a DataFrame.

  Parameters:
    func callable

      Python function, returns a single value from a single value.

    na_action{None, ‘ignore’}, default None

      If ‘ignore’, propagate NaN values, without passing them to func.

    **kwargs

      Additional keyword arguments to pass as keywords arguments to func.

  Returns:
    DataFrame

      Transformed DataFrame.

  See also

  `DataFrame.apply`

    Apply a function along input axis of DataFrame.

  `DataFrame.replace`

    Replace values given in to_replace with value.

  `Series.map`

    Apply a function elementwise on a Series.

  Examples

      >>> df = pd.DataFrame([[1, 2.12], [3.356, 4.567]])
      >>> df
             0      1
      0  1.000  2.120
      1  3.356  4.567

      >>> df.map(lambda x: len(str(x)))
         0  1
      0  3  4
      1  5  5

  Like Series.map, NA values can be ignored:

      >>> df_copy = df.copy()
      >>> df_copy.iloc[0, 0] = pd.NA
      >>> df_copy.map(lambda x: len(str(x)), na_action="ignore")
           0  1
      0  NaN  4
      1  5.0  5

  It is also possible to use map with functions that are not lambda functions:

      >>> df.map(round, ndigits=1)
           0    1
      0  1.0  2.1
      1  3.4  4.6

  Note that a vectorized version of func often exists, which will be much faster. You could square each number elementwise.

      >>> df.map(lambda x: x**2)
                 0          1
      0   1.000000   4.494400
      1  11.262736  20.857489

  But it’s better to avoid map in that case.

      >>> df**2
                 0          1
      0   1.000000   4.494400
      1  11.262736  20.857489