def test_suppresses_parent_exceptions(self):
with suppress(LookupError):
my_dict = {'key': 'value'}
my_dict[4]
self.assertEqual(my_dict, {'key': 'value'})
with suppress(LookupError):
my_list = ['item']
my_list[1]
self.assertEqual(my_list, ['item'])
def test_keyerror_and_index_error(self):
with suppress(KeyError):
my_dict = {'key': 'value'}
my_dict[4]
self.assertEqual(my_dict, {'key': 'value'})
with suppress(IndexError):
my_list = ['item']
my_list[1]
self.assertEqual(my_list, ['item'])
def test_catches_any_number_of_exceptions(self):
with suppress(ValueError, TypeError):
int('hello')
with suppress(IndexError, TypeError):
int(None)
with self.assertRaises(KeyError):
with suppress(IndexError, TypeError):
{0: 1}[1]
with suppress(ValueError, SystemError, IndexError, TypeError):
['item'][1]
def test_does_not_suppress_other_exceptions(self):
with self.assertRaises(KeyError):
with suppress(IndexError):
my_dict = {'key': 'value'}
my_dict[4]
self.assertEqual(my_dict, {'key': 'value'})
with self.assertRaises(IndexError):
with suppress(KeyError):
my_list = ['item']
my_list[1]
self.assertEqual(my_list, ['item'])
def test_suppress_specific_exception(self):
with suppress(ValueError):
x = 1
int('hello')
x = 2
self.assertEqual(x, 1)
with suppress(TypeError):
x = 3
int(None)
x = 4
self.assertEqual(x, 3)
def test_works_when_no_exception_raised(self):
with suppress(Exception):
x = 4
self.assertEqual(x, 4)
def test_allows_exception_to_be_viewed(self):
with suppress(LookupError) as suppressed:
my_dict = {'key': 'value'}
my_dict[4]
self.assertEqual(type(suppressed.exception), KeyError)
self.assertEqual(type(suppressed.traceback), TracebackType)