use pandas Grouper instead of TimeGrouper (#1767)

Author: Joe Hamman

doc/whats-new.rst

@@ -21,8 +21,13 @@ v0.10.1 (unreleased)
 Enhancements
 ~~~~~~~~~~~~
 
-- :py:func:`~plot.contourf()` learned to contour 2D variables that have both a 1D co-ordinate (e.g. time) and a 2D co-ordinate (e.g. depth as a function of time).
+- :py:func:`~plot.contourf()` learned to contour 2D variables that have both a
+  1D co-ordinate (e.g. time) and a 2D co-ordinate (e.g. depth as a function of
+  time) (:issue:`1737`).
   By `Deepak Cherian <https://github.com/dcherian>`_.
+- Use ``pandas.Grouper`` class in xarray resample methods rather than the
+  deprecated ``pandas.TimeGrouper`` class (:issue:`1766`).
+  By `Joe Hamman <https://github.com/jhamman>`_.
 
 
 Bug fixes

xarray/core/common.py

@@ -590,10 +590,9 @@ def resample(self, freq=None, dim=None, how=None, skipna=None,
             raise TypeError("Dimension name should be a string; "
                             "was passed %r" % dim)
         group = DataArray(dim, [(dim.dims, dim)], name=RESAMPLE_DIM)
-        time_grouper = pd.TimeGrouper(freq=freq, closed=closed,
-                                      label=label, base=base)
+        grouper = pd.Grouper(freq=freq, closed=closed, label=label, base=base)
         resampler = self._resample_cls(self, group=group, dim=dim_name,
-                                       grouper=time_grouper,
+                                       grouper=grouper,
                                        resample_dim=RESAMPLE_DIM)
 
         return resampler
@@ -615,9 +614,9 @@ def _resample_immediately(self, freq, dim, how, skipna,
         if isinstance(dim, basestring):
             dim = self[dim]
         group = DataArray(dim, [(dim.dims, dim)], name=RESAMPLE_DIM)
-        time_grouper = pd.TimeGrouper(freq=freq, how=how, closed=closed,
-                                      label=label, base=base)
-        gb = self._groupby_cls(self, group, grouper=time_grouper)
+        grouper = pd.Grouper(freq=freq, how=how, closed=closed, label=label,
+                             base=base)
+        gb = self._groupby_cls(self, group, grouper=grouper)
         if isinstance(how, basestring):
             f = getattr(gb, how)
             if how in ['first', 'last']: