Added repr string for Grouper

Author: tp

pandas/core/groupby.py

@@ -336,6 +336,17 @@ def _get_binner_for_grouping(self, obj):
     def groups(self):
         return self.grouper.groups
 
+    def __repr__(self):
+        if not hasattr(self, '_repr'):
+            defaults = dict(key=None, level=None, freq=None, axis=0,
+                            sort=False)
+            attrs = {k: v for k, v in self.__dict__.items()
+                     if k in defaults and v is not defaults[k]}
+            attrs = ", ".join("{}={!r}".format(k, v) for k, v in attrs.items())
+            cls_name = self.__class__.__name__
+            self._repr = "{}({})".format(cls_name, attrs)
+        return self._repr
+
 
 class GroupByPlot(PandasObject):
     """