io.pytables: handle start/stop in remove and select_coords

pandas/io/pytables.py

@@ -860,7 +860,7 @@ def remove(self, key, where=None, start=None, stop=None):
             raise KeyError('No object named %s in the file' % key)
 
         # remove the node
-        if where is None:
+        if where is None and start is None and stop is None:
             s.group._f_remove(recursive=True)
 
         # delete from the table
@@ -2139,11 +2139,9 @@ def write(self, **kwargs):
         raise NotImplementedError(
             "cannot write on an abstract storer: sublcasses should implement")
 
-    def delete(self, where=None, **kwargs):
-        """support fully deleting the node in its entirety (only) - where
-        specification must be None
-        """
-        if where is None:
+    def delete(self, where=None, start=None, stop=None, **kwargs):
+        """ support fully deleting the node in its entirety (only) - where specification must be None """
+        if where is None and start is None and stop is None:
             self._handle.removeNode(self.group, recursive=True)
             return None
 
@@ -3700,12 +3698,16 @@ def write_data_chunk(self, indexes, mask, values):
         except Exception as detail:
             raise TypeError("tables cannot write this data -> %s" % detail)
 
-    def delete(self, where=None, **kwargs):
+    def delete(self, where=None, start=None, stop=None, **kwargs):
 
         # delete all rows (and return the nrows)
         if where is None or not len(where):
-            nrows = self.nrows
-            self._handle.removeNode(self.group, recursive=True)
+            if start is None and stop is None:
+                nrows = self.nrows
+                self._handle.removeNode(self.group, recursive=True)
+            else:
+                nrows = self.table.removeRows(start=start, stop=stop)
+                self.table.flush()
             return nrows
 
         # infer the data kind
@@ -3714,7 +3716,7 @@ def delete(self, where=None, **kwargs):
 
         # create the selection
         table = self.table
-        self.selection = Selection(self, where, **kwargs)
+        self.selection = Selection(self, where, start=start, stop=stop, **kwargs)
         values = self.selection.select_coords()
 
         # delete the rows in reverse order
@@ -4297,7 +4299,7 @@ def select_coords(self):
         generate the selection
         """
         if self.condition is None:
-            return np.arange(self.table.nrows)
+            return np.arange(0, self.table.nrows)[self.start:self.stop]
 
         return self.table.table.getWhereList(self.condition.format(),
                                              start=self.start, stop=self.stop,

pandas/io/tests/test_pytables.py

@@ -2158,6 +2158,68 @@ def test_remove_where(self):
             # self.assertRaises(ValueError, store.remove,
             #                  'wp2', [('column', ['A', 'D'])])
 
+    def test_remove_startstop(self):
+
+        with ensure_clean_store(self.path) as store:
+
+            wp = tm.makePanel()
+
+            # start
+            store.put('wp1', wp, format='t')
+            n = store.remove('wp1', start=32)
+            assert(n == 120-32)
+            result = store.select('wp1')
+            expected = wp.reindex(major_axis=wp.major_axis[:32//4])
+            assert_panel_equal(result, expected)
+
+            store.put('wp2', wp, format='t')
+            n = store.remove('wp2', start=-32)
+            assert(n == 32)
+            result = store.select('wp2')
+            expected = wp.reindex(major_axis=wp.major_axis[:-32//4])
+            assert_panel_equal(result, expected)
+
+            # stop
+            store.put('wp3', wp, format='t')
+            n = store.remove('wp3', stop=32)
+            assert(n == 32)
+            result = store.select('wp3')
+            expected = wp.reindex(major_axis=wp.major_axis[32//4:])
+            assert_panel_equal(result, expected)
+
+            store.put('wp4', wp, format='t')
+            n = store.remove('wp4', stop=-32)
+            assert(n == 120-32)
+            result = store.select('wp4')
+            expected = wp.reindex(major_axis=wp.major_axis[-32//4:])
+            assert_panel_equal(result, expected)
+
+            # start n stop
+            store.put('wp5', wp, format='t')
+            n = store.remove('wp5', start=16, stop=-16)
+            assert(n == 120-32)
+            result = store.select('wp5')
+            expected = wp.reindex(major_axis=wp.major_axis[:16//4]+wp.major_axis[-16//4:])
+            assert_panel_equal(result, expected)
+
+            store.put('wp6', wp, format='t')
+            n = store.remove('wp6', start=16, stop=16)
+            assert(n == 0)
+            result = store.select('wp6')
+            expected = wp.reindex(major_axis=wp.major_axis)
+            assert_panel_equal(result, expected)
+
+            # with where
+            date = wp.major_axis.take(np.arange(0,30,3))
+            crit = Term('major_axis=date')
+            store.put('wp7', wp, format='t')
+            n = store.remove('wp7', where=[crit], stop=80)
+            assert(n == 28)
+            result = store.select('wp7')
+            expected = wp.reindex(major_axis=wp.major_axis-wp.major_axis[np.arange(0,20,3)])
+            assert_panel_equal(result, expected)
+
+
     def test_remove_crit(self):
 
         with ensure_clean_store(self.path) as store: