change isinstance (#792)

Author: Rubtsowa

sdc/datatypes/hpat_pandas_dataframe_functions.py

@@ -1954,7 +1954,7 @@ def pct_change_overload(df, periods=1, fill_method='pad', limit=None, freq=None)
 
     Limitations
     -----------
-    Parameters ``limit`` and ``freq`` are unsupported.
+    Parameters ``limit`` and ``freq`` are supported only with default value ``None``.
 
     Examples
     --------
@@ -1995,16 +1995,16 @@ def pct_change_overload(df, periods=1, fill_method='pad', limit=None, freq=None)
     ty_checker = TypeChecker('Method {}().'.format(name))
     ty_checker.check(df, DataFrameType)
 
-    if not isinstance(periods, (types.Integer, types.Omitted)):
+    if not isinstance(periods, (types.Integer, types.Omitted)) and periods != 1:
         ty_checker.raise_exc(periods, 'int64', 'periods')
 
     if not isinstance(fill_method, (str, types.UnicodeType, types.StringLiteral, types.NoneType, types.Omitted)):
         ty_checker.raise_exc(fill_method, 'string', 'fill_method')
 
-    if not isinstance(limit, (types.Omitted, types.NoneType)):
+    if not isinstance(limit, (types.Omitted, types.NoneType)) and limit is not None:
         ty_checker.raise_exc(limit, 'None', 'limit')
 
-    if not isinstance(freq, (types.Omitted, types.NoneType)):
+    if not isinstance(freq, (types.Omitted, types.NoneType)) and freq is not None:
         ty_checker.raise_exc(freq, 'None', 'freq')
 
     params = {'periods': 1, 'fill_method': '"pad"', 'limit': None, 'freq': None}

sdc/tests/test_dataframe.py

@@ -2037,6 +2037,18 @@ def test_impl(df):
                            "D": [14, None, 6, 2, 6, 4]})
         pd.testing.assert_frame_equal(hpat_func(df), test_impl(df))
 
+    @skip_sdc_jit
+    def test_pct_change_with_parameters_limit_and_freq(self):
+        def test_impl(df, limit, freq):
+            return df.pct_change(limit=limit, freq=freq)
+
+        hpat_func = sdc.jit(test_impl)
+        df = pd.DataFrame({"A": [14, 4, 5, 4, 1, 55],
+                           "B": [5, 2, None, 3, 2, 32],
+                           "C": [20, 20, 7, 21, 8, None],
+                           "D": [14, None, 6, 2, 6, 4]})
+        pd.testing.assert_frame_equal(hpat_func(df, None, None), test_impl(df, None, None))
+
     @skip_sdc_jit
     def test_pct_change_with_parametrs(self):
         def test_impl(df, periods, method):