Fixed cumulative functions (#127)

* Fixed cumulative functions * Fix formatting * Resolve comments
modin-project · Oct 8, 2018 · ab2ccef · ab2ccef
1 parent 68f2f59
commit ab2ccef
Showing 1 changed file with 17 additions and 0 deletions.
diff --git a/modin/pandas/dataframe.py b/modin/pandas/dataframe.py
@@ -1012,6 +1012,8 @@ def cummax(self, axis=None, skipna=True, *args, **kwargs):
             The cumulative maximum of the DataFrame.
         """
         axis = pandas.DataFrame()._get_axis_number(axis) if axis is not None else 0
+        if axis:
+            self._validate_dtypes()
         return DataFrame(
             data_manager=self._data_manager.cummax(axis=axis, skipna=skipna, **kwargs)
         )
@@ -1027,6 +1029,8 @@ def cummin(self, axis=None, skipna=True, *args, **kwargs):
             The cumulative minimum of the DataFrame.
         """
         axis = pandas.DataFrame()._get_axis_number(axis) if axis is not None else 0
+        if axis:
+            self._validate_dtypes()
         return DataFrame(
             data_manager=self._data_manager.cummin(axis=axis, skipna=skipna, **kwargs)
         )
@@ -1042,6 +1046,7 @@ def cumprod(self, axis=None, skipna=True, *args, **kwargs):
             The cumulative product of the DataFrame.
         """
         axis = pandas.DataFrame()._get_axis_number(axis) if axis is not None else 0
+        self._validate_dtypes(numeric_only=True)
         return DataFrame(
             data_manager=self._data_manager.cumprod(axis=axis, skipna=skipna, **kwargs)
         )
@@ -1057,6 +1062,7 @@ def cumsum(self, axis=None, skipna=True, *args, **kwargs):
             The cumulative sum of the DataFrame.
         """
         axis = pandas.DataFrame()._get_axis_number(axis) if axis is not None else 0
+        self._validate_dtypes(numeric_only=True)
         return DataFrame(
             data_manager=self._data_manager.cumsum(axis=axis, skipna=skipna, **kwargs)
         )
@@ -4629,3 +4635,14 @@ def _validate_other(self, other, axis):
                         "given {1}".format(len(self.columns), len(other))
                     )
         return other
+
+    def _validate_dtypes(self, numeric_only=False):
+        """Helper method to check that all the dtypes are the same"""
+        dtype = self.dtypes[0]
+        for t in self.dtypes:
+            if numeric_only and not is_numeric_dtype(t):
+                raise TypeError("{0} is not a numeric data type".format(t))
+            elif not numeric_only and t != dtype:
+                raise TypeError(
+                    "Cannot compare type '{0}' with type '{1}'".format(t, dtype)
+                )