Refs #26022 -- Used context manager version of assertRaises in tests.

5 files changed, 120 insertions, 64 deletions

diff --git a/tests/forms_tests/tests/test_fields.py b/tests/forms_tests/tests/test_fields.py
index 45545cdb48..b46f897391 100644
--- a/tests/forms_tests/tests/test_fields.py
+++ b/tests/forms_tests/tests/test_fields.py
@@ -149,9 +149,12 @@ class FieldsTests(SimpleTestCase):
         Ensure that setting min_length or max_length to something that is not a
         number returns an exception.
         """
-        self.assertRaises(ValueError, CharField, min_length='a')
-        self.assertRaises(ValueError, CharField, max_length='a')
-        self.assertRaises(ValueError, CharField, 'a')
+        with self.assertRaises(ValueError):
+            CharField(min_length='a')
+        with self.assertRaises(ValueError):
+            CharField(max_length='a')
+        with self.assertRaises(ValueError):
+            CharField('a')
 
     def test_charfield_widget_attrs(self):
         """
@@ -1654,8 +1657,10 @@ class FieldsTests(SimpleTestCase):
     # GenericIPAddressField #######################################################
 
     def test_generic_ipaddress_invalid_arguments(self):
-        self.assertRaises(ValueError, GenericIPAddressField, protocol="hamster")
-        self.assertRaises(ValueError, GenericIPAddressField, protocol="ipv4", unpack_ipv4=True)
+        with self.assertRaises(ValueError):
+            GenericIPAddressField(protocol='hamster')
+        with self.assertRaises(ValueError):
+            GenericIPAddressField(protocol='ipv4', unpack_ipv4=True)
 
     def test_generic_ipaddress_as_generic(self):
         # The edge cases of the IPv6 validation code are not deeply tested
diff --git a/tests/forms_tests/tests/test_forms.py b/tests/forms_tests/tests/test_forms.py
index 00d2045786..66b1737e6f 100644
--- a/tests/forms_tests/tests/test_forms.py
+++ b/tests/forms_tests/tests/test_forms.py
@@ -3227,7 +3227,8 @@ Good luck picking a username that doesn&#39;t already exist.</p>
         """
         p = Person({'first_name': 'John', 'last_name': 'Lennon', 'birthday': 'fakedate'})
         repr(p)
-        self.assertRaises(AttributeError, lambda: p.cleaned_data)
+        with self.assertRaises(AttributeError):
+            p.cleaned_data
         self.assertFalse(p.is_valid())
         self.assertEqual(p.cleaned_data, {'first_name': 'John', 'last_name': 'Lennon'})
 
diff --git a/tests/forms_tests/tests/test_input_formats.py b/tests/forms_tests/tests/test_input_formats.py
index afb2513a95..51118a1470 100644
--- a/tests/forms_tests/tests/test_input_formats.py
+++ b/tests/forms_tests/tests/test_input_formats.py
@@ -19,7 +19,8 @@ class LocalizedTimeTests(SimpleTestCase):
         "TimeFields can parse dates in the default format"
         f = forms.TimeField()
         # Parse a time in an unaccepted format; get an error
-        self.assertRaises(forms.ValidationError, f.clean, '1:30:05 PM')
+        with self.assertRaises(forms.ValidationError):
+            f.clean('1:30:05 PM')
 
         # Parse a time in a valid format, get a parsed result
         result = f.clean('13:30:05')
@@ -45,7 +46,8 @@ class LocalizedTimeTests(SimpleTestCase):
         "Localized TimeFields act as unlocalized widgets"
         f = forms.TimeField(localize=True)
         # Parse a time in an unaccepted format; get an error
-        self.assertRaises(forms.ValidationError, f.clean, '1:30:05 PM')
+        with self.assertRaises(forms.ValidationError):
+            f.clean('1:30:05 PM')
 
         # Parse a time in a valid format, get a parsed result
         result = f.clean('13:30:05')
@@ -67,8 +69,10 @@ class LocalizedTimeTests(SimpleTestCase):
         "TimeFields with manually specified input formats can accept those formats"
         f = forms.TimeField(input_formats=["%H.%M.%S", "%H.%M"])
         # Parse a time in an unaccepted format; get an error
-        self.assertRaises(forms.ValidationError, f.clean, '1:30:05 PM')
-        self.assertRaises(forms.ValidationError, f.clean, '13:30:05')
+        with self.assertRaises(forms.ValidationError):
+            f.clean('1:30:05 PM')
+        with self.assertRaises(forms.ValidationError):
+            f.clean('13:30:05')
 
         # Parse a time in a valid format, get a parsed result
         result = f.clean('13.30.05')
@@ -90,8 +94,10 @@ class LocalizedTimeTests(SimpleTestCase):
         "Localized TimeFields with manually specified input formats can accept those formats"
         f = forms.TimeField(input_formats=["%H.%M.%S", "%H.%M"], localize=True)
         # Parse a time in an unaccepted format; get an error
-        self.assertRaises(forms.ValidationError, f.clean, '1:30:05 PM')
-        self.assertRaises(forms.ValidationError, f.clean, '13:30:05')
+        with self.assertRaises(forms.ValidationError):
+            f.clean('1:30:05 PM')
+        with self.assertRaises(forms.ValidationError):
+            f.clean('13:30:05')
 
         # Parse a time in a valid format, get a parsed result
         result = f.clean('13.30.05')
@@ -116,7 +122,8 @@ class CustomTimeInputFormatsTests(SimpleTestCase):
         "TimeFields can parse dates in the default format"
         f = forms.TimeField()
         # Parse a time in an unaccepted format; get an error
-        self.assertRaises(forms.ValidationError, f.clean, '13:30:05')
+        with self.assertRaises(forms.ValidationError):
+            f.clean('13:30:05')
 
         # Parse a time in a valid format, get a parsed result
         result = f.clean('1:30:05 PM')
@@ -138,7 +145,8 @@ class CustomTimeInputFormatsTests(SimpleTestCase):
         "Localized TimeFields act as unlocalized widgets"
         f = forms.TimeField(localize=True)
         # Parse a time in an unaccepted format; get an error
-        self.assertRaises(forms.ValidationError, f.clean, '13:30:05')
+        with self.assertRaises(forms.ValidationError):
+            f.clean('13:30:05')
 
         # Parse a time in a valid format, get a parsed result
         result = f.clean('1:30:05 PM')
@@ -160,8 +168,10 @@ class CustomTimeInputFormatsTests(SimpleTestCase):
         "TimeFields with manually specified input formats can accept those formats"
         f = forms.TimeField(input_formats=["%H.%M.%S", "%H.%M"])
         # Parse a time in an unaccepted format; get an error
-        self.assertRaises(forms.ValidationError, f.clean, '1:30:05 PM')
-        self.assertRaises(forms.ValidationError, f.clean, '13:30:05')
+        with self.assertRaises(forms.ValidationError):
+            f.clean('1:30:05 PM')
+        with self.assertRaises(forms.ValidationError):
+            f.clean('13:30:05')
 
         # Parse a time in a valid format, get a parsed result
         result = f.clean('13.30.05')
@@ -183,8 +193,10 @@ class CustomTimeInputFormatsTests(SimpleTestCase):
         "Localized TimeFields with manually specified input formats can accept those formats"
         f = forms.TimeField(input_formats=["%H.%M.%S", "%H.%M"], localize=True)
         # Parse a time in an unaccepted format; get an error
-        self.assertRaises(forms.ValidationError, f.clean, '1:30:05 PM')
-        self.assertRaises(forms.ValidationError, f.clean, '13:30:05')
+        with self.assertRaises(forms.ValidationError):
+            f.clean('1:30:05 PM')
+        with self.assertRaises(forms.ValidationError):
+            f.clean('13:30:05')
 
         # Parse a time in a valid format, get a parsed result
         result = f.clean('13.30.05')
@@ -208,7 +220,8 @@ class SimpleTimeFormatTests(SimpleTestCase):
         "TimeFields can parse dates in the default format"
         f = forms.TimeField()
         # Parse a time in an unaccepted format; get an error
-        self.assertRaises(forms.ValidationError, f.clean, '1:30:05 PM')
+        with self.assertRaises(forms.ValidationError):
+            f.clean('1:30:05 PM')
 
         # Parse a time in a valid format, get a parsed result
         result = f.clean('13:30:05')
@@ -230,7 +243,8 @@ class SimpleTimeFormatTests(SimpleTestCase):
         "Localized TimeFields in a non-localized environment act as unlocalized widgets"
         f = forms.TimeField()
         # Parse a time in an unaccepted format; get an error
-        self.assertRaises(forms.ValidationError, f.clean, '1:30:05 PM')
+        with self.assertRaises(forms.ValidationError):
+            f.clean('1:30:05 PM')
 
         # Parse a time in a valid format, get a parsed result
         result = f.clean('13:30:05')
@@ -252,7 +266,8 @@ class SimpleTimeFormatTests(SimpleTestCase):
         "TimeFields with manually specified input formats can accept those formats"
         f = forms.TimeField(input_formats=["%I:%M:%S %p", "%I:%M %p"])
         # Parse a time in an unaccepted format; get an error
-        self.assertRaises(forms.ValidationError, f.clean, '13:30:05')
+        with self.assertRaises(forms.ValidationError):
+            f.clean('13:30:05')
 
         # Parse a time in a valid format, get a parsed result
         result = f.clean('1:30:05 PM')
@@ -274,7 +289,8 @@ class SimpleTimeFormatTests(SimpleTestCase):
         "Localized TimeFields with manually specified input formats can accept those formats"
         f = forms.TimeField(input_formats=["%I:%M:%S %p", "%I:%M %p"], localize=True)
         # Parse a time in an unaccepted format; get an error
-        self.assertRaises(forms.ValidationError, f.clean, '13:30:05')
+        with self.assertRaises(forms.ValidationError):
+            f.clean('13:30:05')
 
         # Parse a time in a valid format, get a parsed result
         result = f.clean('1:30:05 PM')
@@ -305,7 +321,8 @@ class LocalizedDateTests(SimpleTestCase):
         "DateFields can parse dates in the default format"
         f = forms.DateField()
         # Parse a date in an unaccepted format; get an error
-        self.assertRaises(forms.ValidationError, f.clean, '21/12/2010')
+        with self.assertRaises(forms.ValidationError):
+            f.clean('21/12/2010')
 
         # ISO formats are accepted, even if not specified in formats.py
         self.assertEqual(f.clean('2010-12-21'), date(2010, 12, 21))
@@ -330,7 +347,8 @@ class LocalizedDateTests(SimpleTestCase):
         "Localized DateFields act as unlocalized widgets"
         f = forms.DateField(localize=True)
         # Parse a date in an unaccepted format; get an error
-        self.assertRaises(forms.ValidationError, f.clean, '21/12/2010')
+        with self.assertRaises(forms.ValidationError):
+            f.clean('21/12/2010')
 
         # Parse a date in a valid format, get a parsed result
         result = f.clean('21.12.2010')
@@ -352,9 +370,12 @@ class LocalizedDateTests(SimpleTestCase):
         "DateFields with manually specified input formats can accept those formats"
         f = forms.DateField(input_formats=["%m.%d.%Y", "%m-%d-%Y"])
         # Parse a date in an unaccepted format; get an error
-        self.assertRaises(forms.ValidationError, f.clean, '2010-12-21')
-        self.assertRaises(forms.ValidationError, f.clean, '21/12/2010')
-        self.assertRaises(forms.ValidationError, f.clean, '21.12.2010')
+        with self.assertRaises(forms.ValidationError):
+            f.clean('2010-12-21')
+        with self.assertRaises(forms.ValidationError):
+            f.clean('21/12/2010')
+        with self.assertRaises(forms.ValidationError):
+            f.clean('21.12.2010')
 
         # Parse a date in a valid format, get a parsed result
         result = f.clean('12.21.2010')
@@ -376,9 +397,12 @@ class LocalizedDateTests(SimpleTestCase):
         "Localized DateFields with manually specified input formats can accept those formats"
         f = forms.DateField(input_formats=["%m.%d.%Y", "%m-%d-%Y"], localize=True)
         # Parse a date in an unaccepted format; get an error
-        self.assertRaises(forms.ValidationError, f.clean, '2010-12-21')
-        self.assertRaises(forms.ValidationError, f.clean, '21/12/2010')
-        self.assertRaises(forms.ValidationError, f.clean, '21.12.2010')
+        with self.assertRaises(forms.ValidationError):
+            f.clean('2010-12-21')
+        with self.assertRaises(forms.ValidationError):
+            f.clean('21/12/2010')
+        with self.assertRaises(forms.ValidationError):
+            f.clean('21.12.2010')
 
         # Parse a date in a valid format, get a parsed result
         result = f.clean('12.21.2010')
@@ -403,7 +427,8 @@ class CustomDateInputFormatsTests(SimpleTestCase):
         "DateFields can parse dates in the default format"
         f = forms.DateField()
         # Parse a date in an unaccepted format; get an error
-        self.assertRaises(forms.ValidationError, f.clean, '2010-12-21')
+        with self.assertRaises(forms.ValidationError):
+            f.clean('2010-12-21')
 
         # Parse a date in a valid format, get a parsed result
         result = f.clean('21.12.2010')
@@ -425,7 +450,8 @@ class CustomDateInputFormatsTests(SimpleTestCase):
         "Localized DateFields act as unlocalized widgets"
         f = forms.DateField(localize=True)
         # Parse a date in an unaccepted format; get an error
-        self.assertRaises(forms.ValidationError, f.clean, '2010-12-21')
+        with self.assertRaises(forms.ValidationError):
+            f.clean('2010-12-21')
 
         # Parse a date in a valid format, get a parsed result
         result = f.clean('21.12.2010')
@@ -447,8 +473,10 @@ class CustomDateInputFormatsTests(SimpleTestCase):
         "DateFields with manually specified input formats can accept those formats"
         f = forms.DateField(input_formats=["%m.%d.%Y", "%m-%d-%Y"])
         # Parse a date in an unaccepted format; get an error
-        self.assertRaises(forms.ValidationError, f.clean, '21.12.2010')
-        self.assertRaises(forms.ValidationError, f.clean, '2010-12-21')
+        with self.assertRaises(forms.ValidationError):
+            f.clean('21.12.2010')
+        with self.assertRaises(forms.ValidationError):
+            f.clean('2010-12-21')
 
         # Parse a date in a valid format, get a parsed result
         result = f.clean('12.21.2010')
@@ -470,8 +498,10 @@ class CustomDateInputFormatsTests(SimpleTestCase):
         "Localized DateFields with manually specified input formats can accept those formats"
         f = forms.DateField(input_formats=["%m.%d.%Y", "%m-%d-%Y"], localize=True)
         # Parse a date in an unaccepted format; get an error
-        self.assertRaises(forms.ValidationError, f.clean, '21.12.2010')
-        self.assertRaises(forms.ValidationError, f.clean, '2010-12-21')
+        with self.assertRaises(forms.ValidationError):
+            f.clean('21.12.2010')
+        with self.assertRaises(forms.ValidationError):
+            f.clean('2010-12-21')
 
         # Parse a date in a valid format, get a parsed result
         result = f.clean('12.21.2010')
@@ -495,7 +525,8 @@ class SimpleDateFormatTests(SimpleTestCase):
         "DateFields can parse dates in the default format"
         f = forms.DateField()
         # Parse a date in an unaccepted format; get an error
-        self.assertRaises(forms.ValidationError, f.clean, '21.12.2010')
+        with self.assertRaises(forms.ValidationError):
+            f.clean('21.12.2010')
 
         # Parse a date in a valid format, get a parsed result
         result = f.clean('2010-12-21')
@@ -517,7 +548,8 @@ class SimpleDateFormatTests(SimpleTestCase):
         "Localized DateFields in a non-localized environment act as unlocalized widgets"
         f = forms.DateField()
         # Parse a date in an unaccepted format; get an error
-        self.assertRaises(forms.ValidationError, f.clean, '21.12.2010')
+        with self.assertRaises(forms.ValidationError):
+            f.clean('21.12.2010')
 
         # Parse a date in a valid format, get a parsed result
         result = f.clean('2010-12-21')
@@ -539,7 +571,8 @@ class SimpleDateFormatTests(SimpleTestCase):
         "DateFields with manually specified input formats can accept those formats"
         f = forms.DateField(input_formats=["%d.%m.%Y", "%d-%m-%Y"])
         # Parse a date in an unaccepted format; get an error
-        self.assertRaises(forms.ValidationError, f.clean, '2010-12-21')
+        with self.assertRaises(forms.ValidationError):
+            f.clean('2010-12-21')
 
         # Parse a date in a valid format, get a parsed result
         result = f.clean('21.12.2010')
@@ -561,7 +594,8 @@ class SimpleDateFormatTests(SimpleTestCase):
         "Localized DateFields with manually specified input formats can accept those formats"
         f = forms.DateField(input_formats=["%d.%m.%Y", "%d-%m-%Y"], localize=True)
         # Parse a date in an unaccepted format; get an error
-        self.assertRaises(forms.ValidationError, f.clean, '2010-12-21')
+        with self.assertRaises(forms.ValidationError):
+            f.clean('2010-12-21')
 
         # Parse a date in a valid format, get a parsed result
         result = f.clean('21.12.2010')
@@ -592,7 +626,8 @@ class LocalizedDateTimeTests(SimpleTestCase):
         "DateTimeFields can parse dates in the default format"
         f = forms.DateTimeField()
         # Parse a date in an unaccepted format; get an error
-        self.assertRaises(forms.ValidationError, f.clean, '1:30:05 PM 21/12/2010')
+        with self.assertRaises(forms.ValidationError):
+            f.clean('1:30:05 PM 21/12/2010')
 
         # ISO formats are accepted, even if not specified in formats.py
         self.assertEqual(f.clean('2010-12-21 13:30:05'), datetime(2010, 12, 21, 13, 30, 5))
@@ -617,7 +652,8 @@ class LocalizedDateTimeTests(SimpleTestCase):
         "Localized DateTimeFields act as unlocalized widgets"
         f = forms.DateTimeField(localize=True)
         # Parse a date in an unaccepted format; get an error
-        self.assertRaises(forms.ValidationError, f.clean, '1:30:05 PM 21/12/2010')
+        with self.assertRaises(forms.ValidationError):
+            f.clean('1:30:05 PM 21/12/2010')
 
         # Parse a date in a valid format, get a parsed result
         result = f.clean('21.12.2010 13:30:05')
@@ -639,9 +675,12 @@ class LocalizedDateTimeTests(SimpleTestCase):
         "DateTimeFields with manually specified input formats can accept those formats"
         f = forms.DateTimeField(input_formats=["%H.%M.%S %m.%d.%Y", "%H.%M %m-%d-%Y"])
         # Parse a date in an unaccepted format; get an error
-        self.assertRaises(forms.ValidationError, f.clean, '2010-12-21 13:30:05 13:30:05')
-        self.assertRaises(forms.ValidationError, f.clean, '1:30:05 PM 21/12/2010')
-        self.assertRaises(forms.ValidationError, f.clean, '13:30:05 21.12.2010')
+        with self.assertRaises(forms.ValidationError):
+            f.clean('2010-12-21 13:30:05 13:30:05')
+        with self.assertRaises(forms.ValidationError):
+            f.clean('1:30:05 PM 21/12/2010')
+        with self.assertRaises(forms.ValidationError):
+            f.clean('13:30:05 21.12.2010')
 
         # Parse a date in a valid format, get a parsed result
         result = f.clean('13.30.05 12.21.2010')
@@ -663,9 +702,12 @@ class LocalizedDateTimeTests(SimpleTestCase):
         "Localized DateTimeFields with manually specified input formats can accept those formats"
         f = forms.DateTimeField(input_formats=["%H.%M.%S %m.%d.%Y", "%H.%M %m-%d-%Y"], localize=True)
         # Parse a date in an unaccepted format; get an error
-        self.assertRaises(forms.ValidationError, f.clean, '2010-12-21 13:30:05')
-        self.assertRaises(forms.ValidationError, f.clean, '1:30:05 PM 21/12/2010')
-        self.assertRaises(forms.ValidationError, f.clean, '13:30:05 21.12.2010')
+        with self.assertRaises(forms.ValidationError):
+            f.clean('2010-12-21 13:30:05')
+        with self.assertRaises(forms.ValidationError):
+            f.clean('1:30:05 PM 21/12/2010')
+        with self.assertRaises(forms.ValidationError):
+            f.clean('13:30:05 21.12.2010')
 
         # Parse a date in a valid format, get a parsed result
         result = f.clean('13.30.05 12.21.2010')
@@ -690,7 +732,8 @@ class CustomDateTimeInputFormatsTests(SimpleTestCase):
         "DateTimeFields can parse dates in the default format"
         f = forms.DateTimeField()
         # Parse a date in an unaccepted format; get an error
-        self.assertRaises(forms.ValidationError, f.clean, '2010-12-21 13:30:05')
+        with self.assertRaises(forms.ValidationError):
+            f.clean('2010-12-21 13:30:05')
 
         # Parse a date in a valid format, get a parsed result
         result = f.clean('1:30:05 PM 21/12/2010')
@@ -712,7 +755,8 @@ class CustomDateTimeInputFormatsTests(SimpleTestCase):
         "Localized DateTimeFields act as unlocalized widgets"
         f = forms.DateTimeField(localize=True)
         # Parse a date in an unaccepted format; get an error
-        self.assertRaises(forms.ValidationError, f.clean, '2010-12-21 13:30:05')
+        with self.assertRaises(forms.ValidationError):
+            f.clean('2010-12-21 13:30:05')
 
         # Parse a date in a valid format, get a parsed result
         result = f.clean('1:30:05 PM 21/12/2010')
@@ -734,8 +778,10 @@ class CustomDateTimeInputFormatsTests(SimpleTestCase):
         "DateTimeFields with manually specified input formats can accept those formats"
         f = forms.DateTimeField(input_formats=["%m.%d.%Y %H:%M:%S", "%m-%d-%Y %H:%M"])
         # Parse a date in an unaccepted format; get an error
-        self.assertRaises(forms.ValidationError, f.clean, '13:30:05 21.12.2010')
-        self.assertRaises(forms.ValidationError, f.clean, '2010-12-21 13:30:05')
+        with self.assertRaises(forms.ValidationError):
+            f.clean('13:30:05 21.12.2010')
+        with self.assertRaises(forms.ValidationError):
+            f.clean('2010-12-21 13:30:05')
 
         # Parse a date in a valid format, get a parsed result
         result = f.clean('12.21.2010 13:30:05')
@@ -757,8 +803,10 @@ class CustomDateTimeInputFormatsTests(SimpleTestCase):
         "Localized DateTimeFields with manually specified input formats can accept those formats"
         f = forms.DateTimeField(input_formats=["%m.%d.%Y %H:%M:%S", "%m-%d-%Y %H:%M"], localize=True)
         # Parse a date in an unaccepted format; get an error
-        self.assertRaises(forms.ValidationError, f.clean, '13:30:05 21.12.2010')
-        self.assertRaises(forms.ValidationError, f.clean, '2010-12-21 13:30:05')
+        with self.assertRaises(forms.ValidationError):
+            f.clean('13:30:05 21.12.2010')
+        with self.assertRaises(forms.ValidationError):
+            f.clean('2010-12-21 13:30:05')
 
         # Parse a date in a valid format, get a parsed result
         result = f.clean('12.21.2010 13:30:05')
@@ -782,7 +830,8 @@ class SimpleDateTimeFormatTests(SimpleTestCase):
         "DateTimeFields can parse dates in the default format"
         f = forms.DateTimeField()
         # Parse a date in an unaccepted format; get an error
-        self.assertRaises(forms.ValidationError, f.clean, '13:30:05 21.12.2010')
+        with self.assertRaises(forms.ValidationError):
+            f.clean('13:30:05 21.12.2010')
 
         # Parse a date in a valid format, get a parsed result
         result = f.clean('2010-12-21 13:30:05')
@@ -804,7 +853,8 @@ class SimpleDateTimeFormatTests(SimpleTestCase):
         "Localized DateTimeFields in a non-localized environment act as unlocalized widgets"
         f = forms.DateTimeField()
         # Parse a date in an unaccepted format; get an error
-        self.assertRaises(forms.ValidationError, f.clean, '13:30:05 21.12.2010')
+        with self.assertRaises(forms.ValidationError):
+            f.clean('13:30:05 21.12.2010')
 
         # Parse a date in a valid format, get a parsed result
         result = f.clean('2010-12-21 13:30:05')
@@ -826,7 +876,8 @@ class SimpleDateTimeFormatTests(SimpleTestCase):
         "DateTimeFields with manually specified input formats can accept those formats"
         f = forms.DateTimeField(input_formats=["%I:%M:%S %p %d.%m.%Y", "%I:%M %p %d-%m-%Y"])
         # Parse a date in an unaccepted format; get an error
-        self.assertRaises(forms.ValidationError, f.clean, '2010-12-21 13:30:05')
+        with self.assertRaises(forms.ValidationError):
+            f.clean('2010-12-21 13:30:05')
 
         # Parse a date in a valid format, get a parsed result
         result = f.clean('1:30:05 PM 21.12.2010')
@@ -848,7 +899,8 @@ class SimpleDateTimeFormatTests(SimpleTestCase):
         "Localized DateTimeFields with manually specified input formats can accept those formats"
         f = forms.DateTimeField(input_formats=["%I:%M:%S %p %d.%m.%Y", "%I:%M %p %d-%m-%Y"], localize=True)
         # Parse a date in an unaccepted format; get an error
-        self.assertRaises(forms.ValidationError, f.clean, '2010-12-21 13:30:05')
+        with self.assertRaises(forms.ValidationError):
+            f.clean('2010-12-21 13:30:05')
 
         # Parse a date in a valid format, get a parsed result
         result = f.clean('1:30:05 PM 21.12.2010')
diff --git a/tests/forms_tests/tests/test_validators.py b/tests/forms_tests/tests/test_validators.py
index cb7104756a..8c348d600d 100644
--- a/tests/forms_tests/tests/test_validators.py
+++ b/tests/forms_tests/tests/test_validators.py
@@ -45,12 +45,9 @@ class TestFieldWithValidators(TestCase):
             'string': '2 is not correct',
             'ignore_case_string': "IgnORE Case strIng",
         })
-        self.assertRaises(ValidationError, form.fields['full_name'].clean, 'not int nor mail')
-
-        try:
+        with self.assertRaises(ValidationError) as e:
             form.fields['full_name'].clean('not int nor mail')
-        except ValidationError as e:
-            self.assertEqual(2, len(e.messages))
+        self.assertEqual(2, len(e.exception.messages))
 
         self.assertFalse(form.is_valid())
         self.assertEqual(form.errors['string'], ["Letters only."])
diff --git a/tests/forms_tests/tests/tests.py b/tests/forms_tests/tests/tests.py
index 992dbc851e..f1bd66fc6b 100644
--- a/tests/forms_tests/tests/tests.py
+++ b/tests/forms_tests/tests/tests.py
@@ -251,7 +251,8 @@ class RelatedModelFormTests(SimpleTestCase):
             model = A
             fields = '__all__'
 
-        self.assertRaises(ValueError, ModelFormMetaclass, str('Form'), (ModelForm,), {'Meta': Meta})
+        with self.assertRaises(ValueError):
+            ModelFormMetaclass(str('Form'), (ModelForm,), {'Meta': Meta})
 
         class B(models.Model):
             pass