TST: create separate test test_to_datetime_format_YYYYMMDD_overflow() for pandas-dev#25512

Author: nathalier

pandas/tests/indexes/datetimes/test_tools.py

@@ -83,48 +83,50 @@ def test_to_datetime_format_YYYYMMDD(self, cache):
         result = to_datetime(s, format='%Y%m%d', cache=cache)
         assert_series_equal(result, expected)
 
+        # coercion
+        # GH 7930
+        s = Series([20121231, 20141231, 99991231])
+        result = pd.to_datetime(s, format='%Y%m%d', errors='ignore',
+                                cache=cache)
+        expected = Series([datetime(2012, 12, 31),
+                           datetime(2014, 12, 31), datetime(9999, 12, 31)],
+                          dtype=object)
+        tm.assert_series_equal(result, expected)
+
+        result = pd.to_datetime(s, format='%Y%m%d', errors='coerce',
+                                cache=cache)
+        expected = Series(['20121231', '20141231', 'NaT'], dtype='M8[ns]')
+        tm.assert_series_equal(result, expected)
+
+    @pytest.mark.parametrize('cache', [True, False])
+    def test_to_datetime_format_YYYYMMDD_overflow(self, cache):
         # GH 25512
         # NaN before strings with invalid date values, errors=coerce
         s = Series(['19801222', np.nan, '20010012', '10019999'])
         result = pd.to_datetime(s, format='%Y%m%d', errors='coerce',
                                 cache=cache)
         expected = Series([Timestamp('19801222'), np.nan, np.nan, np.nan])
-        tm.assert_series_equal(result, expected)
+        assert_series_equal(result, expected)
 
         # NaN after strings with invalid date values, errors=coerce
         s = Series(['19801222', '20010012', '10019999', np.nan])
         result = pd.to_datetime(s, format='%Y%m%d', errors='coerce',
                                 cache=cache)
         expected = Series([Timestamp('19801222'), np.nan, np.nan, np.nan])
-        tm.assert_series_equal(result, expected)
+        assert_series_equal(result, expected)
 
         # NaN before integers with invalid date values, errors=coerce
         s = Series([20190813, np.nan, 20010012, 20019999])
         result = pd.to_datetime(s, format='%Y%m%d', errors='coerce',
                                 cache=cache)
         expected = Series([Timestamp('20190813'), np.nan, np.nan, np.nan])
-        tm.assert_series_equal(result, expected)
+        assert_series_equal(result, expected)
 
         # NaN after integers with invalid date values, errors=coerce
         s = Series([20190813, 20010012, np.nan, 20019999])
         result = pd.to_datetime(s, format='%Y%m%d', errors='coerce',
                                 cache=cache)
         expected = Series([Timestamp('20190813'), np.nan, np.nan, np.nan])
-        tm.assert_series_equal(result, expected)
-
-        # coercion
-        # GH 7930
-        s = Series([20121231, 20141231, 99991231])
-        result = pd.to_datetime(s, format='%Y%m%d', errors='ignore',
-                                cache=cache)
-        expected = Series([datetime(2012, 12, 31),
-                           datetime(2014, 12, 31), datetime(9999, 12, 31)],
-                          dtype=object)
-        tm.assert_series_equal(result, expected)
-
-        result = pd.to_datetime(s, format='%Y%m%d', errors='coerce',
-                                cache=cache)
-        expected = Series(['20121231', '20141231', 'NaT'], dtype='M8[ns]')
         assert_series_equal(result, expected)
 
     @pytest.mark.parametrize('cache', [True, False])