Changed catch_warnings to assertions

Author: Chris Bertinato

pandas/io/parsers.py

@@ -3149,7 +3149,7 @@ def converter(*date_cols):
                     dayfirst=dayfirst,
                     errors='ignore',
                     infer_datetime_format=infer_datetime_format
-                ).to_pydatetime()
+                )
             except ValueError:
                 return tools.to_datetime(
                     parsing.try_parse_dates(strs, dayfirst=dayfirst))

pandas/tests/indexes/datetimes/test_tools.py

@@ -4,7 +4,6 @@
 from datetime import datetime, time
 from distutils.version import LooseVersion
 import locale
-from warnings import catch_warnings, simplefilter
 
 import dateutil
 from dateutil.parser import parse
@@ -222,9 +221,7 @@ def test_to_datetime_format_weeks(self, cache):
     def test_to_datetime_parse_tzname_or_tzoffset(self, box, const,
                                                   fmt, dates, expected_dates):
         # GH 13486
-        with catch_warnings():
-            simplefilter("ignore", FutureWarning)
-
+        with tm.assert_produces_warning(FutureWarning):
             result = pd.to_datetime(dates, format=fmt, box=box)
             expected = const(expected_dates)
             tm.assert_equal(result, expected)
@@ -260,11 +257,8 @@ def test_to_datetime_dtarr(self, tz):
         result = to_datetime(arr)
         assert result is arr
 
-        with catch_warnings():
-            simplefilter("ignore", FutureWarning)
-
-            result = to_datetime(arr, box=True)
-            assert result is arr
+        result = to_datetime(arr)
+        assert result is arr
 
     def test_to_datetime_pydatetime(self):
         actual = pd.to_datetime(datetime(2008, 1, 15))
@@ -364,8 +358,7 @@ def test_to_datetime_dt64s(self, cache):
     def test_to_datetime_array_of_dt64s(self, cache):
         dts = [np.datetime64('2000-01-01'), np.datetime64('2000-01-02'), ]
 
-        with catch_warnings():
-            simplefilter("ignore", FutureWarning)
+        with tm.assert_produces_warning(FutureWarning):
 
             # Assuming all datetimes are in bounds, to_datetime() returns
             # an array that is equal to Timestamp() parsing
@@ -380,6 +373,7 @@ def test_to_datetime_array_of_dt64s(self, cache):
             pytest.raises(ValueError, pd.to_datetime, dts_with_oob,
                           errors='raise')
 
+        with tm.assert_produces_warning(FutureWarning):
             tm.assert_numpy_array_equal(
                 pd.to_datetime(dts_with_oob, box=False, errors='coerce',
                                cache=cache),
@@ -393,6 +387,7 @@ def test_to_datetime_array_of_dt64s(self, cache):
                 )
             )
 
+        with tm.assert_produces_warning(FutureWarning):
             # With errors='ignore', out of bounds datetime64s
             # are converted to their .item(), which depending on the version of
             # numpy is either a python datetime.datetime or datetime.date
@@ -574,11 +569,11 @@ def test_to_datetime_cache(self, utc, format, box, constructor):
         test_dates = [date] * 10**5
         data = constructor(test_dates)
 
-        with catch_warnings():
-            simplefilter("ignore", FutureWarning)
-
+        with tm.assert_produces_warning(FutureWarning):
             result = pd.to_datetime(data, utc=utc, format=format, box=box,
                                     cache=True)
+
+        with tm.assert_produces_warning(FutureWarning):
             expected = pd.to_datetime(data, utc=utc, format=format, box=box,
                                       cache=False)
         if box:
@@ -634,8 +629,7 @@ def test_iso_8601_strings_same_offset_no_box(self):
         # GH 22446
         data = ['2018-01-04 09:01:00+09:00', '2018-01-04 09:02:00+09:00']
 
-        with catch_warnings():
-            simplefilter("ignore", FutureWarning)
+        with tm.assert_produces_warning(FutureWarning):
             result = pd.to_datetime(data, box=False)
 
         expected = np.array([
@@ -993,8 +987,7 @@ def test_dataframe_box_false(self):
                            'month': [2, 3],
                            'day': [4, 5]})
 
-        with catch_warnings():
-            simplefilter("ignore", FutureWarning)
+        with tm.assert_produces_warning(FutureWarning):
             result = pd.to_datetime(df, box=False)
 
         expected = np.array(['2015-02-04', '2016-03-05'],
@@ -1139,13 +1132,14 @@ def test_to_datetime_types(self, cache):
     def test_to_datetime_unprocessable_input(self, cache, box, klass):
         # GH 4928
         # GH 21864
-        with catch_warnings():
-            simplefilter("ignore", FutureWarning)
+        with tm.assert_produces_warning(FutureWarning):
             result = to_datetime([1, '1'], errors='ignore', cache=cache,
                                  box=box)
 
             expected = klass(np.array([1, '1'], dtype='O'))
             tm.assert_equal(result, expected)
+
+        with tm.assert_produces_warning(FutureWarning):
             pytest.raises(TypeError, to_datetime, [1, '1'], errors='raise',
                           cache=cache, box=box)
 

pandas/tests/indexes/timedeltas/test_tools.py

@@ -1,5 +1,4 @@
 from datetime import time, timedelta
-from warnings import catch_warnings, simplefilter
 
 import numpy as np
 import pytest
@@ -20,12 +19,12 @@ def conv(v):
 
         d1 = np.timedelta64(1, 'D')
 
-        with catch_warnings():
-            simplefilter("ignore", FutureWarning)
-
+        with tm.assert_produces_warning(FutureWarning):
             assert (to_timedelta('1 days 06:05:01.00003', box=False) ==
                     conv(d1 + np.timedelta64(6 * 3600 + 5 * 60 + 1, 's') +
                          np.timedelta64(30, 'us')))
+
+        with tm.assert_produces_warning(FutureWarning):
             assert (to_timedelta('15.5us', box=False) ==
                     conv(np.timedelta64(15500, 'ns')))
 
@@ -41,9 +40,7 @@ def conv(v):
         expected = pd.Index(np.array([np.timedelta64(1, 's')]))
         tm.assert_index_equal(result, expected)
 
-        with catch_warnings():
-            simplefilter("ignore", FutureWarning)
-
+        with tm.assert_produces_warning(FutureWarning):
             # ints
             result = np.timedelta64(0, 'ns')
             expected = to_timedelta(0, box=False)
@@ -60,15 +57,14 @@ def conv(v):
         expected = to_timedelta([0, 10], unit='s')
         tm.assert_index_equal(result, expected)
 
-        with catch_warnings():
-            simplefilter("ignore", FutureWarning)
-
+        with tm.assert_produces_warning(FutureWarning):
             # single element conversion
             v = timedelta(seconds=1)
             result = to_timedelta(v, box=False)
             expected = np.timedelta64(timedelta(seconds=1))
             assert result == expected
 
+        with tm.assert_produces_warning(FutureWarning):
             v = np.timedelta64(timedelta(seconds=1))
             result = to_timedelta(v, box=False)
             expected = np.timedelta64(timedelta(seconds=1))
@@ -100,20 +96,21 @@ def conv(v):
         expected = TimedeltaIndex([np.timedelta64(1, 'D')] * 5)
         tm.assert_index_equal(result, expected)
 
-        with catch_warnings():
-            simplefilter("ignore", FutureWarning)
-
+        with tm.assert_produces_warning(FutureWarning):
             # Test with lists as input when box=false
             expected = np.array(np.arange(3) * 1000000000, dtype='timedelta64[ns]')
             result = to_timedelta(range(3), unit='s', box=False)
             tm.assert_numpy_array_equal(expected, result)
 
+        with tm.assert_produces_warning(FutureWarning):
             result = to_timedelta(np.arange(3), unit='s', box=False)
             tm.assert_numpy_array_equal(expected, result)
 
+        with tm.assert_produces_warning(FutureWarning):
             result = to_timedelta([0, 1, 2], unit='s', box=False)
             tm.assert_numpy_array_equal(expected, result)
 
+        with tm.assert_produces_warning(FutureWarning):
             # Tests with fractional seconds as input:
             expected = np.array(
                 [0, 500000000, 800000000, 1200000000], dtype='timedelta64[ns]')