GH14883 fix

Added searchsorted implementation to MultiIndex

Author: ShaharBental

pandas/indexes/multi.py

@@ -32,7 +32,9 @@
 from pandas.core.base import FrozenList
 import pandas.core.base as base
 from pandas.util.decorators import (Appender, cache_readonly,
-                                    deprecate, deprecate_kwarg)
+                                    deprecate, deprecate_kwarg,
+                                    Substitution)
+
 import pandas.core.common as com
 import pandas.core.missing as missing
 import pandas.core.algorithms as algos
@@ -1470,6 +1472,26 @@ def get_indexer(self, target, method=None, limit=None, tolerance=None):
 
         return _ensure_platform_int(indexer)
 
+    def searchsorted(self, value, side='left', sorter=None):
+        ans = []
+        for val in value:
+            left_index=0
+            right_index=None
+            for dim in range(0,self.labels.__len__()):
+                v=self.levels[dim][self.labels[dim]]
+                if right_index==None: right_index=len(v)
+                v=v[left_index:right_index]
+                if (dim<self.labels.__len__()-1):
+                    left_addition = v.searchsorted(val[dim],'left')
+                    right_addition = v.searchsorted(val[dim],'right')
+                    right_index=left_index+right_addition
+                    left_index=left_index+left_addition
+                else:
+                    ans.append(left_index+ v.searchsorted(val[dim],side))
+        return ans
+
+
+
     def reindex(self, target, method=None, level=None, limit=None,
                 tolerance=None):
         """

pandas/tests/test_multilevel.py

@@ -2448,6 +2448,18 @@ def test_iloc_mi(self):
 
         assert_frame_equal(result, expected)
 
+    def test_searchsorted(self):
+        # GH 14833
+        # Test if MultiIndex searchsorted returns the right results for both left and right search sorted
+        df_mi = pd.MultiIndex([[0,1], ["a","c"]], [[0,0,1], [0,1,1]])
+        expected_left = list([0,1,3,1])
+        expected_right = list([0,1,3,2])
+
+        result_left = df_mi.searchsorted([(-1, "b"),(0,"b"),(2,"a"),(0,"c")],side='left')
+        result_right = df_mi.searchsorted([(-1, "b"),(0,"b"),(2,"a"),(0,"c")],side='right')
+
+        self.assertEqual(result_left,expected_left)
+        self.assertEqual(result_right,expected_right)
 
 if __name__ == '__main__':
     nose.runmodule(argv=[__file__, '-vvs', '-x', '--pdb', '--pdb-failure'],