text: # Python test set -- part 5, built-in exceptions
  
  import copy
  import os
  import sys
  import unittest
  import pickle
  import weakref
  import errno
  
  from test.support import (TESTFN, captured_stderr, check_impl_detail,
                            check_warnings, cpython_only, gc_collect, run_unittest,
                            no_tracing, unlink, import_module)
  
  class NaiveException(Exception):
      def __init__(self, x):
          self.x = x
  
  class SlottedNaiveException(Exception):
      __slots__ = ('x',)
      def __init__(self, x):
          self.x = x
  
  class BrokenStrException(Exception):
      def __str__(self):
          raise Exception("str() is broken")
  
  # XXX This is not really enough, each *operation* should be tested!
  
  class ExceptionTests(unittest.TestCase):
  
      def raise_catch(self, exc, excname):
          try:
              raise exc("spam")
          except exc as err:
              buf1 = str(err)
          try:
              raise exc("spam")
          except exc as err:
              buf2 = str(err)
          self.assertEqual(buf1, buf2)
          self.assertEqual(exc.__name__, excname)
  
      def testRaising(self):
          self.raise_catch(AttributeError, "AttributeError")
          self.assertRaises(AttributeError, getattr, sys, "undefined_attribute")
  
          self.raise_catch(EOFError, "EOFError")
          fp = open(TESTFN, 'w')
          fp.close()
          fp = open(TESTFN, 'r')
          savestdin = sys.stdin
          try:
              try:
                  import marshal
                  marshal.loads(b'')
              except EOFError:
                  pass
          finally:
              sys.stdin = savestdin
              fp.close()
              unlink(TESTFN)
  
          self.raise_catch(OSError, "OSError")
          self.assertRaises(OSError, open, 'this file does not exist', 'r')
  
          self.raise_catch(ImportError, "ImportError")
          self.assertRaises(ImportError, __import__, "undefined_module")
  
          self.raise_catch(IndexError, "IndexError")
          x = []
          self.assertRaises(IndexError, x.__getitem__, 10)
  
          self.raise_catch(KeyError, "KeyError")
          x = {}
          self.assertRaises(KeyError, x.__getitem__, 'key')
  
          self.raise_catch(KeyboardInterrupt, "KeyboardInterrupt")
  
          self.raise_catch(MemoryError, "MemoryError")
  
          self.raise_catch(NameError, "NameError")
          try: x = undefined_variable
          except NameError: pass
  
          self.raise_catch(OverflowError, "OverflowError")
          x = 1
          for dummy in range(128):
              x += x  # this simply shouldn't blow up
  
          self.raise_catch(RuntimeError, "RuntimeError")
          self.raise_catch(RecursionError, "RecursionError")
  
          self.raise_catch(SyntaxError, "SyntaxError")
          try: exec('/\n')
          except SyntaxError: pass
  
          self.raise_catch(IndentationError, "IndentationError")
  
          self.raise_catch(TabError, "TabError")
          try: compile("try:\n\t1/0\n    \t1/0\nfinally:\n pass\n",
                       '<string>', 'exec')
          except TabError: pass
          else: self.fail("TabError not raised")
  
          self.raise_catch(SystemError, "SystemError")
  
          self.raise_catch(SystemExit, "SystemExit")
          self.assertRaises(SystemExit, sys.exit, 0)
  
          self.raise_catch(TypeError, "TypeError")
          try: [] + ()
          except TypeError: pass
  
          self.raise_catch(ValueError, "ValueError")
          self.assertRaises(ValueError, chr, 17<<16)
  
          self.raise_catch(ZeroDivisionError, "ZeroDivisionError")
          try: x = 1/0
          except ZeroDivisionError: pass
  
          self.raise_catch(Exception, "Exception")
          try: x = 1/0
          except Exception as e: pass
  
          self.raise_catch(StopAsyncIteration, "StopAsyncIteration")
  
      def testSyntaxErrorMessage(self):
          # make sure the right exception message is raised for each of
          # these code fragments
  
          def ckmsg(src, msg):
              try:
                  compile(src, '<fragment>', 'exec')
              except SyntaxError as e:
                  if e.msg != msg:
                      self.fail("expected %s, got %s" % (msg, e.msg))
              else:
                  self.fail("failed to get expected SyntaxError")
  
          s = '''while 1:
              try:
                  pass
              finally:
                  continue'''
  
          if not sys.platform.startswith('java'):
              ckmsg(s, "'continue' not supported inside 'finally' clause")
  
          s = '''if 1:
          try:
              continue
          except:
              pass'''
  
          ckmsg(s, "'continue' not properly in loop")
          ckmsg("continue\n", "'continue' not properly in loop")
  
      def testSyntaxErrorOffset(self):
          def check(src, lineno, offset):
              with self.assertRaises(SyntaxError) as cm:
                  compile(src, '<fragment>', 'exec')
              self.assertEqual(cm.exception.lineno, lineno)
              self.assertEqual(cm.exception.offset, offset)
  
          check('def fact(x):\n\treturn x!\n', 2, 10)
          check('1 +\n', 1, 4)
          check('def spam():\n  print(1)\n print(2)', 3, 10)
          check('Python = "Python" +', 1, 20)
          check('Python = "\u1e54\xfd\u0163\u0125\xf2\xf1" +', 1, 20)
  
      @cpython_only
      def testSettingException(self):
          # test that setting an exception at the C level works even if the
          # exception object can't be constructed.
  
          class BadException(Exception):
              def __init__(self_):
                  raise RuntimeError("can't instantiate BadException")
  
          class InvalidException:
              pass
  
          def test_capi1():
              import _testcapi
              try:
                  _testcapi.raise_exception(BadException, 1)
              except TypeError as err:
                  exc, err, tb = sys.exc_info()
                  co = tb.tb_frame.f_code
                  self.assertEqual(co.co_name, "test_capi1")
                  self.assertTrue(co.co_filename.endswith('test_exceptions.py'))
              else:
                  self.fail("Expected exception")
  
          def test_capi2():
              import _testcapi
              try:
                  _testcapi.raise_exception(BadException, 0)
              except RuntimeError as err:
                  exc, err, tb = sys.exc_info()
                  co = tb.tb_frame.f_code
                  self.assertEqual(co.co_name, "__init__")
                  self.assertTrue(co.co_filename.endswith('test_exceptions.py'))
                  co2 = tb.tb_frame.f_back.f_code
                  self.assertEqual(co2.co_name, "test_capi2")
              else:
                  self.fail("Expected exception")
  
          def test_capi3():
              import _testcapi
              self.assertRaises(SystemError, _testcapi.raise_exception,
                                InvalidException, 1)
  
          if not sys.platform.startswith('java'):
              test_capi1()
              test_capi2()
              test_capi3()
  
      def test_WindowsError(self):
          try:
              WindowsError
          except NameError:
              pass
          else:
              self.assertIs(WindowsError, OSError)
              self.assertEqual(str(OSError(1001)), "1001")
              self.assertEqual(str(OSError(1001, "message")),
                               "[Errno 1001] message")
              # POSIX errno (9 aka EBADF) is untranslated
              w = OSError(9, 'foo', 'bar')
              self.assertEqual(w.errno, 9)
              self.assertEqual(w.winerror, None)
              self.assertEqual(str(w), "[Errno 9] foo: 'bar'")
              # ERROR_PATH_NOT_FOUND (win error 3) becomes ENOENT (2)
              w = OSError(0, 'foo', 'bar', 3)
              self.assertEqual(w.errno, 2)
              self.assertEqual(w.winerror, 3)
              self.assertEqual(w.strerror, 'foo')
              self.assertEqual(w.filename, 'bar')
              self.assertEqual(w.filename2, None)
              self.assertEqual(str(w), "[WinError 3] foo: 'bar'")
              # Unknown win error becomes EINVAL (22)
              w = OSError(0, 'foo', None, 1001)
              self.assertEqual(w.errno, 22)
              self.assertEqual(w.winerror, 1001)
              self.assertEqual(w.strerror, 'foo')
              self.assertEqual(w.filename, None)
              self.assertEqual(w.filename2, None)
              self.assertEqual(str(w), "[WinError 1001] foo")
              # Non-numeric "errno"
              w = OSError('bar', 'foo')
              self.assertEqual(w.errno, 'bar')
              self.assertEqual(w.winerror, None)
              self.assertEqual(w.strerror, 'foo')
              self.assertEqual(w.filename, None)
              self.assertEqual(w.filename2, None)
  
      @unittest.skipUnless(sys.platform == 'win32',
                           'test specific to Windows')
      def test_windows_message(self):
          """Should fill in unknown error code in Windows error message"""
          ctypes = import_module('ctypes')
          # this error code has no message, Python formats it as hexadecimal
          code = 3765269347
          with self.assertRaisesRegex(OSError, 'Windows Error 0x%x' % code):
              ctypes.pythonapi.PyErr_SetFromWindowsErr(code)
  
      def testAttributes(self):
          # test that exception attributes are happy
  
          exceptionList = [
              (BaseException, (), {'args' : ()}),
              (BaseException, (1, ), {'args' : (1,)}),
              (BaseException, ('foo',),
                  {'args' : ('foo',)}),
              (BaseException, ('foo', 1),
                  {'args' : ('foo', 1)}),
              (SystemExit, ('foo',),
                  {'args' : ('foo',), 'code' : 'foo'}),
              (OSError, ('foo',),
                  {'args' : ('foo',), 'filename' : None, 'filename2' : None,
                   'errno' : None, 'strerror' : None}),
              (OSError, ('foo', 'bar'),
                  {'args' : ('foo', 'bar'),
                   'filename' : None, 'filename2' : None,
                   'errno' : 'foo', 'strerror' : 'bar'}),
              (OSError, ('foo', 'bar', 'baz'),
                  {'args' : ('foo', 'bar'),
                   'filename' : 'baz', 'filename2' : None,
                   'errno' : 'foo', 'strerror' : 'bar'}),
              (OSError, ('foo', 'bar', 'baz', None, 'quux'),
                  {'args' : ('foo', 'bar'), 'filename' : 'baz', 'filename2': 'quux'}),
              (OSError, ('errnoStr', 'strErrorStr', 'filenameStr'),
                  {'args' : ('errnoStr', 'strErrorStr'),
                   'strerror' : 'strErrorStr', 'errno' : 'errnoStr',
                   'filename' : 'filenameStr'}),
              (OSError, (1, 'strErrorStr', 'filenameStr'),
                  {'args' : (1, 'strErrorStr'), 'errno' : 1,
                   'strerror' : 'strErrorStr',
                   'filename' : 'filenameStr', 'filename2' : None}),
              (SyntaxError, (), {'msg' : None, 'text' : None,
                  'filename' : None, 'lineno' : None, 'offset' : None,
                  'print_file_and_line' : None}),
              (SyntaxError, ('msgStr',),
                  {'args' : ('msgStr',), 'text' : None,
                   'print_file_and_line' : None, 'msg' : 'msgStr',
                   'filename' : None, 'lineno' : None, 'offset' : None}),
              (SyntaxError, ('msgStr', ('filenameStr', 'linenoStr', 'offsetStr',
                             'textStr')),
                  {'offset' : 'offsetStr', 'text' : 'textStr',
                   'args' : ('msgStr', ('filenameStr', 'linenoStr',
                                        'offsetStr', 'textStr')),
                   'print_file_and_line' : None, 'msg' : 'msgStr',
                   'filename' : 'filenameStr', 'lineno' : 'linenoStr'}),
              (SyntaxError, ('msgStr', 'filenameStr', 'linenoStr', 'offsetStr',
                             'textStr', 'print_file_and_lineStr'),
                  {'text' : None,
                   'args' : ('msgStr', 'filenameStr', 'linenoStr', 'offsetStr',
                             'textStr', 'print_file_and_lineStr'),
                   'print_file_and_line' : None, 'msg' : 'msgStr',
                   'filename' : None, 'lineno' : None, 'offset' : None}),
              (UnicodeError, (), {'args' : (),}),
              (UnicodeEncodeError, ('ascii', 'a', 0, 1,
                                    'ordinal not in range'),
                  {'args' : ('ascii', 'a', 0, 1,
                                             'ordinal not in range'),
                   'encoding' : 'ascii', 'object' : 'a',
                   'start' : 0, 'reason' : 'ordinal not in range'}),
              (UnicodeDecodeError, ('ascii', bytearray(b'\xff'), 0, 1,
                                    'ordinal not in range'),
                  {'args' : ('ascii', bytearray(b'\xff'), 0, 1,
                                             'ordinal not in range'),
                   'encoding' : 'ascii', 'object' : b'\xff',
                   'start' : 0, 'reason' : 'ordinal not in range'}),
              (UnicodeDecodeError, ('ascii', b'\xff', 0, 1,
                                    'ordinal not in range'),
                  {'args' : ('ascii', b'\xff', 0, 1,
                                             'ordinal not in range'),
                   'encoding' : 'ascii', 'object' : b'\xff',
                   'start' : 0, 'reason' : 'ordinal not in range'}),
              (UnicodeTranslateError, ("\u3042", 0, 1, "ouch"),
                  {'args' : ('\u3042', 0, 1, 'ouch'),
                   'object' : '\u3042', 'reason' : 'ouch',
                   'start' : 0, 'end' : 1}),
              (NaiveException, ('foo',),
                  {'args': ('foo',), 'x': 'foo'}),
              (SlottedNaiveException, ('foo',),
                  {'args': ('foo',), 'x': 'foo'}),
          ]
          try:
              # More tests are in test_WindowsError
              exceptionList.append(
                  (WindowsError, (1, 'strErrorStr', 'filenameStr'),
                      {'args' : (1, 'strErrorStr'),
                       'strerror' : 'strErrorStr', 'winerror' : None,
                       'errno' : 1,
                       'filename' : 'filenameStr', 'filename2' : None})
              )
          except NameError:
              pass
  
          for exc, args, expected in exceptionList:
              try:
                  e = exc(*args)
              except:
                  print("\nexc=%r, args=%r" % (exc, args), file=sys.stderr)
                  raise
              else:
                  # Verify module name
                  if not type(e).__name__.endswith('NaiveException'):
                      self.assertEqual(type(e).__module__, 'builtins')
                  # Verify no ref leaks in Exc_str()
                  s = str(e)
                  for checkArgName in expected:
                      value = getattr(e, checkArgName)
                      self.assertEqual(repr(value),
                                       repr(expected[checkArgName]),
                                       '%r.%s == %r, expected %r' % (
                                       e, checkArgName,
                                       value, expected[checkArgName]))
  
                  # test for pickling support
                  for p in [pickle]:
                      for protocol in range(p.HIGHEST_PROTOCOL + 1):
                          s = p.dumps(e, protocol)
                          new = p.loads(s)
                          for checkArgName in expected:
                              got = repr(getattr(new, checkArgName))
                              want = repr(expected[checkArgName])
                              self.assertEqual(got, want,
                                               'pickled "%r", attribute "%s' %
                                               (e, checkArgName))
  
      def testWithTraceback(self):
          try:
              raise IndexError(4)
          except:
              tb = sys.exc_info()[2]
  
          e = BaseException().with_traceback(tb)
          self.assertIsInstance(e, BaseException)
          self.assertEqual(e.__traceback__, tb)
  
          e = IndexError(5).with_traceback(tb)
          self.assertIsInstance(e, IndexError)
          self.assertEqual(e.__traceback__, tb)
  
          class MyException(Exception):
              pass
  
          e = MyException().with_traceback(tb)
          self.assertIsInstance(e, MyException)
          self.assertEqual(e.__traceback__, tb)
  
      def testInvalidTraceback(self):
          try:
              Exception().__traceback__ = 5
          except TypeError as e:
              self.assertIn("__traceback__ must be a traceback", str(e))
          else:
              self.fail("No exception raised")
  
      def testInvalidAttrs(self):
          self.assertRaises(TypeError, setattr, Exception(), '__cause__', 1)
          self.assertRaises(TypeError, delattr, Exception(), '__cause__')
          self.assertRaises(TypeError, setattr, Exception(), '__context__', 1)
          self.assertRaises(TypeError, delattr, Exception(), '__context__')
  
      def testNoneClearsTracebackAttr(self):
          try:
              raise IndexError(4)
          except:
              tb = sys.exc_info()[2]
  
          e = Exception()
          e.__traceback__ = tb
          e.__traceback__ = None
          self.assertEqual(e.__traceback__, None)
  
      def testChainingAttrs(self):
          e = Exception()
          self.assertIsNone(e.__context__)
          self.assertIsNone(e.__cause__)
  
          e = TypeError()
          self.assertIsNone(e.__context__)
          self.assertIsNone(e.__cause__)
  
          class MyException(OSError):
              pass
  
          e = MyException()
          self.assertIsNone(e.__context__)
          self.assertIsNone(e.__cause__)
  
      def testChainingDescriptors(self):
          try:
              raise Exception()
          except Exception as exc:
              e = exc
  
          self.assertIsNone(e.__context__)
          self.assertIsNone(e.__cause__)
          self.assertFalse(e.__suppress_context__)
  
          e.__context__ = NameError()
          e.__cause__ = None
          self.assertIsInstance(e.__context__, NameError)
          self.assertIsNone(e.__cause__)
          self.assertTrue(e.__suppress_context__)
          e.__suppress_context__ = False
          self.assertFalse(e.__suppress_context__)
  
      def testKeywordArgs(self):
          # test that builtin exception don't take keyword args,
          # but user-defined subclasses can if they want
          self.assertRaises(TypeError, BaseException, a=1)
  
          class DerivedException(BaseException):
              def __init__(self, fancy_arg):
                  BaseException.__init__(self)
                  self.fancy_arg = fancy_arg
  
          x = DerivedException(fancy_arg=42)
          self.assertEqual(x.fancy_arg, 42)
  
      @no_tracing
      def testInfiniteRecursion(self):
          def f():
              return f()
          self.assertRaises(RecursionError, f)
  
          def g():
              try:
                  return g()
              except ValueError:
                  return -1
          self.assertRaises(RecursionError, g)
  
      def test_str(self):
          # Make sure both instances and classes have a str representation.
          self.assertTrue(str(Exception))
          self.assertTrue(str(Exception('a')))
          self.assertTrue(str(Exception('a', 'b')))
  
      def testExceptionCleanupNames(self):
          # Make sure the local variable bound to the exception instance by
          # an "except" statement is only visible inside the except block.
          try:
              raise Exception()
          except Exception as e:
              self.assertTrue(e)
              del e
          self.assertNotIn('e', locals())
  
      def testExceptionCleanupState(self):
          # Make sure exception state is cleaned up as soon as the except
          # block is left. See #2507
  
          class MyException(Exception):
              def __init__(self, obj):
                  self.obj = obj
          class MyObj:
              pass
  
          def inner_raising_func():
              # Create some references in exception value and traceback
              local_ref = obj
              raise MyException(obj)
  
          # Qualified "except" with "as"
          obj = MyObj()
          wr = weakref.ref(obj)
          try:
              inner_raising_func()
          except MyException as e:
              pass
          obj = None
          obj = wr()
          self.assertTrue(obj is None, "%s" % obj)
  
          # Qualified "except" without "as"
          obj = MyObj()
          wr = weakref.ref(obj)
          try:
              inner_raising_func()
          except MyException:
              pass
          obj = None
          obj = wr()
          self.assertTrue(obj is None, "%s" % obj)
  
          # Bare "except"
          obj = MyObj()
          wr = weakref.ref(obj)
          try:
              inner_raising_func()
          except:
              pass
          obj = None
          obj = wr()
          self.assertTrue(obj is None, "%s" % obj)
  
          # "except" with premature block leave
          obj = MyObj()
          wr = weakref.ref(obj)
          for i in [0]:
              try:
                  inner_raising_func()
              except:
                  break
          obj = None
          obj = wr()
          self.assertTrue(obj is None, "%s" % obj)
  
          # "except" block raising another exception
          obj = MyObj()
          wr = weakref.ref(obj)
          try:
              try:
                  inner_raising_func()
              except:
                  raise KeyError
          except KeyError as e:
              # We want to test that the except block above got rid of
              # the exception raised in inner_raising_func(), but it
              # also ends up in the __context__ of the KeyError, so we
              # must clear the latter manually for our test to succeed.
              e.__context__ = None
              obj = None
              obj = wr()
              # guarantee no ref cycles on CPython (don't gc_collect)
              if check_impl_detail(cpython=False):
                  gc_collect()
              self.assertTrue(obj is None, "%s" % obj)
  
          # Some complicated construct
          obj = MyObj()
          wr = weakref.ref(obj)
          try:
              inner_raising_func()
          except MyException:
              try:
                  try:
                      raise
                  finally:
                      raise
              except MyException:
                  pass
          obj = None
          if check_impl_detail(cpython=False):
              gc_collect()
          obj = wr()
          self.assertTrue(obj is None, "%s" % obj)
  
          # Inside an exception-silencing "with" block
          class Context:
              def __enter__(self):
                  return self
              def __exit__ (self, exc_type, exc_value, exc_tb):
                  return True
          obj = MyObj()
          wr = weakref.ref(obj)
          with Context():
              inner_raising_func()
          obj = None
          if check_impl_detail(cpython=False):
              gc_collect()
          obj = wr()
          self.assertTrue(obj is None, "%s" % obj)
  
      def test_exception_target_in_nested_scope(self):
          # issue 4617: This used to raise a SyntaxError
          # "can not delete variable 'e' referenced in nested scope"
          def print_error():
              e
          try:
              something
          except Exception as e:
              print_error()
              # implicit "del e" here
  
      def test_generator_leaking(self):
          # Test that generator exception state doesn't leak into the calling
          # frame
          def yield_raise():
              try:
                  raise KeyError("caught")
              except KeyError:
                  yield sys.exc_info()[0]
                  yield sys.exc_info()[0]
              yield sys.exc_info()[0]
          g = yield_raise()
          self.assertEqual(next(g), KeyError)
          self.assertEqual(sys.exc_info()[0], None)
          self.assertEqual(next(g), KeyError)
          self.assertEqual(sys.exc_info()[0], None)
          self.assertEqual(next(g), None)
  
          # Same test, but inside an exception handler
          try:
              raise TypeError("foo")
          except TypeError:
              g = yield_raise()
              self.assertEqual(next(g), KeyError)
              self.assertEqual(sys.exc_info()[0], TypeError)
              self.assertEqual(next(g), KeyError)
              self.assertEqual(sys.exc_info()[0], TypeError)
              self.assertEqual(next(g), TypeError)
              del g
              self.assertEqual(sys.exc_info()[0], TypeError)
  
      def test_generator_leaking2(self):
          # See issue 12475.
          def g():
              yield
          try:
              raise RuntimeError
          except RuntimeError:
              it = g()
              next(it)
          try:
              next(it)
          except StopIteration:
              pass
          self.assertEqual(sys.exc_info(), (None, None, None))
  
      def test_generator_leaking3(self):
          # See issue #23353.  When gen.throw() is called, the caller's
          # exception state should be save and restored.
          def g():
              try:
                  yield
              except ZeroDivisionError:
                  yield sys.exc_info()[1]
          it = g()
          next(it)
          try:
              1/0
          except ZeroDivisionError as e:
              self.assertIs(sys.exc_info()[1], e)
              gen_exc = it.throw(e)
              self.assertIs(sys.exc_info()[1], e)
              self.assertIs(gen_exc, e)
          self.assertEqual(sys.exc_info(), (None, None, None))
  
      def test_generator_leaking4(self):
          # See issue #23353.  When an exception is raised by a generator,
          # the caller's exception state should still be restored.
          def g():
              try:
                  1/0
              except ZeroDivisionError:
                  yield sys.exc_info()[0]
                  raise
          it = g()
          try:
              raise TypeError
          except TypeError:
              # The caller's exception state (TypeError) is temporarily
              # saved in the generator.
              tp = next(it)
          self.assertIs(tp, ZeroDivisionError)
          try:
              next(it)
              # We can't check it immediately, but while next() returns
              # with an exception, it shouldn't have restored the old
              # exception state (TypeError).
          except ZeroDivisionError as e:
              self.assertIs(sys.exc_info()[1], e)
          # We used to find TypeError here.
          self.assertEqual(sys.exc_info(), (None, None, None))
  
      def test_generator_doesnt_retain_old_exc(self):
          def g():
              self.assertIsInstance(sys.exc_info()[1], RuntimeError)
              yield
              self.assertEqual(sys.exc_info(), (None, None, None))
          it = g()
          try:
              raise RuntimeError
          except RuntimeError:
              next(it)
          self.assertRaises(StopIteration, next, it)
  
      def test_generator_finalizing_and_exc_info(self):
          # See #7173
          def simple_gen():
              yield 1
          def run_gen():
              gen = simple_gen()
              try:
                  raise RuntimeError
              except RuntimeError:
                  return next(gen)
          run_gen()
          gc_collect()
          self.assertEqual(sys.exc_info(), (None, None, None))
  
      def _check_generator_cleanup_exc_state(self, testfunc):
          # Issue #12791: exception state is cleaned up as soon as a generator
          # is closed (reference cycles are broken).
          class MyException(Exception):
              def __init__(self, obj):
                  self.obj = obj
          class MyObj:
              pass
  
          def raising_gen():
              try:
                  raise MyException(obj)
              except MyException:
                  yield
  
          obj = MyObj()
          wr = weakref.ref(obj)
          g = raising_gen()
          next(g)
          testfunc(g)
          g = obj = None
          obj = wr()
          self.assertIs(obj, None)
  
      def test_generator_throw_cleanup_exc_state(self):
          def do_throw(g):
              try:
                  g.throw(RuntimeError())
              except RuntimeError:
                  pass
          self._check_generator_cleanup_exc_state(do_throw)
  
      def test_generator_close_cleanup_exc_state(self):
          def do_close(g):
              g.close()
          self._check_generator_cleanup_exc_state(do_close)
  
      def test_generator_del_cleanup_exc_state(self):
          def do_del(g):
              g = None
          self._check_generator_cleanup_exc_state(do_del)
  
      def test_generator_next_cleanup_exc_state(self):
          def do_next(g):
              try:
                  next(g)
              except StopIteration:
                  pass
              else:
                  self.fail("should have raised StopIteration")
          self._check_generator_cleanup_exc_state(do_next)
  
      def test_generator_send_cleanup_exc_state(self):
          def do_send(g):
              try:
                  g.send(None)
              except StopIteration:
                  pass
              else:
                  self.fail("should have raised StopIteration")
          self._check_generator_cleanup_exc_state(do_send)
  
      def test_3114(self):
          # Bug #3114: in its destructor, MyObject retrieves a pointer to
          # obsolete and/or deallocated objects.
          class MyObject:
              def __del__(self):
                  nonlocal e
                  e = sys.exc_info()
          e = ()
          try:
              raise Exception(MyObject())
          except:
              pass
          self.assertEqual(e, (None, None, None))
  
      def test_unicode_change_attributes(self):
          # See issue 7309. This was a crasher.
  
          u = UnicodeEncodeError('baz', 'xxxxx', 1, 5, 'foo')
          self.assertEqual(str(u), "'baz' codec can't encode characters in position 1-4: foo")
          u.end = 2
          self.assertEqual(str(u), "'baz' codec can't encode character '\\x78' in position 1: foo")
          u.end = 5
          u.reason = 0x345345345345345345
          self.assertEqual(str(u), "'baz' codec can't encode characters in position 1-4: 965230951443685724997")
          u.encoding = 4000
          self.assertEqual(str(u), "'4000' codec can't encode characters in position 1-4: 965230951443685724997")
          u.start = 1000
          self.assertEqual(str(u), "'4000' codec can't encode characters in position 1000-4: 965230951443685724997")
  
          u = UnicodeDecodeError('baz', b'xxxxx', 1, 5, 'foo')
          self.assertEqual(str(u), "'baz' codec can't decode bytes in position 1-4: foo")
          u.end = 2
          self.assertEqual(str(u), "'baz' codec can't decode byte 0x78 in position 1: foo")
          u.end = 5
          u.reason = 0x345345345345345345
          self.assertEqual(str(u), "'baz' codec can't decode bytes in position 1-4: 965230951443685724997")
          u.encoding = 4000
          self.assertEqual(str(u), "'4000' codec can't decode bytes in position 1-4: 965230951443685724997")
          u.start = 1000
          self.assertEqual(str(u), "'4000' codec can't decode bytes in position 1000-4: 965230951443685724997")
  
          u = UnicodeTranslateError('xxxx', 1, 5, 'foo')
          self.assertEqual(str(u), "can't translate characters in position 1-4: foo")
          u.end = 2
          self.assertEqual(str(u), "can't translate character '\\x78' in position 1: foo")
          u.end = 5
          u.reason = 0x345345345345345345
          self.assertEqual(str(u), "can't translate characters in position 1-4: 965230951443685724997")
          u.start = 1000
          self.assertEqual(str(u), "can't translate characters in position 1000-4: 965230951443685724997")
  
      def test_unicode_errors_no_object(self):
          # See issue #21134.
          klasses = UnicodeEncodeError, UnicodeDecodeError, UnicodeTranslateError
          for klass in klasses:
              self.assertEqual(str(klass.__new__(klass)), "")
  
      @no_tracing
      def test_badisinstance(self):
          # Bug #2542: if issubclass(e, MyException) raises an exception,
          # it should be ignored
          class Meta(type):
              def __subclasscheck__(cls, subclass):
                  raise ValueError()
          class MyException(Exception, metaclass=Meta):
              pass
  
          with captured_stderr() as stderr:
              try:
                  raise KeyError()
              except MyException as e:
                  self.fail("exception should not be a MyException")
              except KeyError:
                  pass
              except:
                  self.fail("Should have raised KeyError")
              else:
                  self.fail("Should have raised KeyError")
  
          def g():
              try:
                  return g()
              except RecursionError:
                  return sys.exc_info()
          e, v, tb = g()
          self.assertTrue(isinstance(v, RecursionError), type(v))
          self.assertIn("maximum recursion depth exceeded", str(v))
  
  
      @cpython_only
      def test_MemoryError(self):
          # PyErr_NoMemory always raises the same exception instance.
          # Check that the traceback is not doubled.
          import traceback
          from _testcapi import raise_memoryerror
          def raiseMemError():
              try:
                  raise_memoryerror()
              except MemoryError as e:
                  tb = e.__traceback__
              else:
                  self.fail("Should have raises a MemoryError")
              return traceback.format_tb(tb)
  
          tb1 = raiseMemError()
          tb2 = raiseMemError()
          self.assertEqual(tb1, tb2)
  
      @cpython_only
      def test_exception_with_doc(self):
          import _testcapi
          doc2 = "This is a test docstring."
          doc4 = "This is another test docstring."
  
          self.assertRaises(SystemError, _testcapi.make_exception_with_doc,
                            "error1")
  
          # test basic usage of PyErr_NewException
          error1 = _testcapi.make_exception_with_doc("_testcapi.error1")
          self.assertIs(type(error1), type)
          self.assertTrue(issubclass(error1, Exception))
          self.assertIsNone(error1.__doc__)
  
          # test with given docstring
          error2 = _testcapi.make_exception_with_doc("_testcapi.error2", doc2)
          self.assertEqual(error2.__doc__, doc2)
  
          # test with explicit base (without docstring)
          error3 = _testcapi.make_exception_with_doc("_testcapi.error3",
                                                     base=error2)
          self.assertTrue(issubclass(error3, error2))
  
          # test with explicit base tuple
          class C(object):
              pass
          error4 = _testcapi.make_exception_with_doc("_testcapi.error4", doc4,
                                                     (error3, C))
          self.assertTrue(issubclass(error4, error3))
          self.assertTrue(issubclass(error4, C))
          self.assertEqual(error4.__doc__, doc4)
  
          # test with explicit dictionary
          error5 = _testcapi.make_exception_with_doc("_testcapi.error5", "",
                                                     error4, {'a': 1})
          self.assertTrue(issubclass(error5, error4))
          self.assertEqual(error5.a, 1)
          self.assertEqual(error5.__doc__, "")
  
      @cpython_only
      def test_memory_error_cleanup(self):
          # Issue #5437: preallocated MemoryError instances should not keep
          # traceback objects alive.
          from _testcapi import raise_memoryerror
          class C:
              pass
          wr = None
          def inner():
              nonlocal wr
              c = C()
              wr = weakref.ref(c)
              raise_memoryerror()
          # We cannot use assertRaises since it manually deletes the traceback
          try:
              inner()
          except MemoryError as e:
              self.assertNotEqual(wr(), None)
          else:
              self.fail("MemoryError not raised")
          self.assertEqual(wr(), None)
  
      @no_tracing
      def test_recursion_error_cleanup(self):
          # Same test as above, but with "recursion exceeded" errors
          class C:
              pass
          wr = None
          def inner():
              nonlocal wr
              c = C()
              wr = weakref.ref(c)
              inner()
          # We cannot use assertRaises since it manually deletes the traceback
          try:
              inner()
          except RecursionError as e:
              self.assertNotEqual(wr(), None)
          else:
              self.fail("RecursionError not raised")
          self.assertEqual(wr(), None)
  
      def test_errno_ENOTDIR(self):
          # Issue #12802: "not a directory" errors are ENOTDIR even on Windows
          with self.assertRaises(OSError) as cm:
              os.listdir(__file__)
          self.assertEqual(cm.exception.errno, errno.ENOTDIR, cm.exception)
  
      def test_unraisable(self):
          # Issue #22836: PyErr_WriteUnraisable() should give sensible reports
          class BrokenDel:
              def __del__(self):
                  exc = ValueError("del is broken")
                  # The following line is included in the traceback report:
                  raise exc
  
          class BrokenRepr(BrokenDel):
              def __repr__(self):
                  raise AttributeError("repr() is broken")
  
          class BrokenExceptionDel:
              def __del__(self):
                  exc = BrokenStrException()
                  # The following line is included in the traceback report:
                  raise exc
  
          for test_class in (BrokenDel, BrokenRepr, BrokenExceptionDel):
              with self.subTest(test_class):
                  obj = test_class()
                  with captured_stderr() as stderr:
                      del obj
                  report = stderr.getvalue()
                  self.assertIn("Exception ignored", report)
                  if test_class is BrokenRepr:
                      self.assertIn("<object repr() failed>", report)
                  else:
                      self.assertIn(test_class.__del__.__qualname__, report)
                  self.assertIn("test_exceptions.py", report)
                  self.assertIn("raise exc", report)
                  if test_class is BrokenExceptionDel:
                      self.assertIn("BrokenStrException", report)
                      self.assertIn("<exception str() failed>", report)
                  else:
                      self.assertIn("ValueError", report)
                      self.assertIn("del is broken", report)
                  self.assertTrue(report.endswith("\n"))
  
      def test_unhandled(self):
          # Check for sensible reporting of unhandled exceptions
          for exc_type in (ValueError, BrokenStrException):
              with self.subTest(exc_type):
                  try:
                      exc = exc_type("test message")
                      # The following line is included in the traceback report:
                      raise exc
                  except exc_type:
                      with captured_stderr() as stderr:
                          sys.__excepthook__(*sys.exc_info())
                  report = stderr.getvalue()
                  self.assertIn("test_exceptions.py", report)
                  self.assertIn("raise exc", report)
                  self.assertIn(exc_type.__name__, report)
                  if exc_type is BrokenStrException:
                      self.assertIn("<exception str() failed>", report)
                  else:
                      self.assertIn("test message", report)
                  self.assertTrue(report.endswith("\n"))
  
  
  class ImportErrorTests(unittest.TestCase):
  
      def test_attributes(self):
          # Setting 'name' and 'path' should not be a problem.
          exc = ImportError('test')
          self.assertIsNone(exc.name)
          self.assertIsNone(exc.path)
  
          exc = ImportError('test', name='somemodule')
          self.assertEqual(exc.name, 'somemodule')
          self.assertIsNone(exc.path)
  
          exc = ImportError('test', path='somepath')
          self.assertEqual(exc.path, 'somepath')
          self.assertIsNone(exc.name)
  
          exc = ImportError('test', path='somepath', name='somename')
          self.assertEqual(exc.name, 'somename')
          self.assertEqual(exc.path, 'somepath')
  
          msg = "'invalid' is an invalid keyword argument for this function"
          with self.assertRaisesRegex(TypeError, msg):
              ImportError('test', invalid='keyword')
  
          with self.assertRaisesRegex(TypeError, msg):
              ImportError('test', name='name', invalid='keyword')
  
          with self.assertRaisesRegex(TypeError, msg):
              ImportError('test', path='path', invalid='keyword')
  
          with self.assertRaisesRegex(TypeError, msg):
              ImportError(invalid='keyword')
  
          with self.assertRaisesRegex(TypeError, msg):
              ImportError('test', invalid='keyword', another=True)
  
      def test_non_str_argument(self):
          # Issue #15778
          with check_warnings(('', BytesWarning), quiet=True):
              arg = b'abc'
              exc = ImportError(arg)
              self.assertEqual(str(arg), str(exc))
  
      def test_copy_pickle(self):
          for kwargs in (dict(),
                         dict(name='somename'),
                         dict(path='somepath'),
                         dict(name='somename', path='somepath')):
              orig = ImportError('test', **kwargs)
              for proto in range(pickle.HIGHEST_PROTOCOL + 1):
                  exc = pickle.loads(pickle.dumps(orig, proto))
                  self.assertEqual(exc.args, ('test',))
                  self.assertEqual(exc.msg, 'test')
                  self.assertEqual(exc.name, orig.name)
                  self.assertEqual(exc.path, orig.path)
              for c in copy.copy, copy.deepcopy:
                  exc = c(orig)
                  self.assertEqual(exc.args, ('test',))
                  self.assertEqual(exc.msg, 'test')
                  self.assertEqual(exc.name, orig.name)
                  self.assertEqual(exc.path, orig.path)
  
  
  if __name__ == '__main__':
      unittest.main()
  