# dask.dataframe.tseries.resample.Resampler.sem

Resampler.sem()

  Compute standard error of the mean of groups, excluding missing values.

  This docstring was copied from pandas.core.resample.Resampler.sem.

  Some inconsistencies with the Dask version may exist.

  For multiple groupings, the result index will be a MultiIndex.

  Parameters:
    ddof int, default 1 (Not supported in Dask)

      Degrees of freedom.

    numeric_only bool, default False (Not supported in Dask)

      Include only float, int or boolean data.

      Added in version 1.5.0.

      Changed in version 2.0.0: numeric_only now defaults to `False`.

  Returns:
    Series or DataFrame

      Standard error of the mean of values within each group.

  Examples

  For SeriesGroupBy:

      >>> lst = ['a', 'a', 'b', 'b']
      >>> ser = pd.Series([5, 10, 8, 14], index=lst)
      >>> ser
      a     5
      a    10
      b     8
      b    14
      dtype: int64
      >>> ser.groupby(level=0).sem()
      a    2.5
      b    3.0
      dtype: float64

  For DataFrameGroupBy:

      >>> data = [[1, 12, 11], [1, 15, 2], [2, 5, 8], [2, 6, 12]]
      >>> df = pd.DataFrame(data, columns=["a", "b", "c"],
      ...                   index=["tuna", "salmon", "catfish", "goldfish"])
      >>> df
                 a   b   c
          tuna   1  12  11
        salmon   1  15   2
       catfish   2   5   8
      goldfish   2   6  12
      >>> df.groupby("a").sem()
            b  c
      a
      1    1.5  4.5
      2    0.5  2.0

  For Resampler:

      >>> ser = pd.Series([1, 3, 2, 4, 3, 8],
      ...                 index=pd.DatetimeIndex(['2023-01-01',
      ...                                         '2023-01-10',
      ...                                         '2023-01-15',
      ...                                         '2023-02-01',
      ...                                         '2023-02-10',
      ...                                         '2023-02-15']))
      >>> ser.resample('MS').sem()
      2023-01-01    0.577350
      2023-02-01    1.527525
      Freq: MS, dtype: float64