DataArrayGroupBy.sum(dim=None, axis=None, skipna=None, **kwargs)[source]

Reduce this DataArrayGroupBy’s data by applying sum along some dimension(s).

  • dim (str or sequence of str, optional) – Dimension(s) over which to apply sum.

  • axis (int or sequence of int, optional) – Axis(es) over which to apply sum. Only one of the ‘dim’ and ‘axis’ arguments can be supplied. If neither are supplied, then sum is calculated over axes.

  • skipna (bool, optional) – If True, skip missing values (as marked by NaN). By default, only skips missing values for float dtypes; other dtypes either do not have a sentinel missing value (int) or skipna=True has not been implemented (object, datetime64 or timedelta64).

  • min_count (int, default: None) – The required number of valid values to perform the operation. If fewer than min_count non-NA values are present the result will be NA. Only used if skipna is set to True or defaults to True for the array’s dtype. New in version 0.10.8: Added with the default being None. Changed in version 0.17.0: if specified on an integer array and skipna=True, the result will be a float array.

  • keep_attrs (bool, optional) – If True, the attributes (attrs) will be copied from the original object to the new one. If False (default), the new object will be returned without attributes.

  • **kwargs (dict) – Additional keyword arguments passed on to the appropriate array function for calculating sum on this object’s data.


reduced (DataArrayGroupBy) – New DataArrayGroupBy object with sum applied to its data and the indicated dimension(s) removed.