# Python test set -- part 5, built-in exceptions
import copy
import os
import sys
import unittest
import pickle
import weakref
import errno
from codecs import BOM_UTF8
from itertools import product
from textwrap import dedent
from test.support import (captured_stderr, check_impl_detail,
cpython_only, gc_collect,
no_tracing, script_helper,
SuppressCrashReport,
force_not_colorized)
from test.support.import_helper import import_module
from test.support.os_helper import TESTFN, unlink
from test.support.warnings_helper import check_warnings
from test import support
try:
import _testcapi
from _testcapi import INT_MAX
except ImportError:
_testcapi = None
INT_MAX = 2**31 - 1
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):
with self.subTest(exc=exc, excname=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', encoding="utf-8")
fp.close()
fp = open(TESTFN, 'r', encoding="utf-8")
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):
with self.subTest(src=src, msg=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 = '''if 1:
try:
continue
except:
pass'''
ckmsg(s, "'continue' not properly in loop")
ckmsg("continue\n", "'continue' not properly in loop")
ckmsg("f'{6 0}'", "invalid syntax. Perhaps you forgot a comma?")
def testSyntaxErrorMissingParens(self):
def ckmsg(src, msg, exception=SyntaxError):
try:
compile(src, '<fragment>', 'exec')
except exception as e:
if e.msg != msg:
self.fail("expected %s, got %s" % (msg, e.msg))
else:
self.fail("failed to get expected SyntaxError")
s = '''print "old style"'''
ckmsg(s, "Missing parentheses in call to 'print'. Did you mean print(...)?")
s = '''print "old style",'''
ckmsg(s, "Missing parentheses in call to 'print'. Did you mean print(...)?")
s = 'print f(a+b,c)'
ckmsg(s, "Missing parentheses in call to 'print'. Did you mean print(...)?")
s = '''exec "old style"'''
ckmsg(s, "Missing parentheses in call to 'exec'. Did you mean exec(...)?")
s = 'exec f(a+b,c)'
ckmsg(s, "Missing parentheses in call to 'exec'. Did you mean exec(...)?")
# Check that we don't incorrectly identify '(...)' as an expression to the right
# of 'print'
s = 'print (a+b,c) $ 42'
ckmsg(s, "invalid syntax")
s = 'exec (a+b,c) $ 42'
ckmsg(s, "invalid syntax")
# should not apply to subclasses, see issue #31161
s = '''if True:\nprint "No indent"'''
ckmsg(s, "expected an indented block after 'if' statement on line 1", IndentationError)
s = '''if True:\n print()\n\texec "mixed tabs and spaces"'''
ckmsg(s, "inconsistent use of tabs and spaces in indentation", TabError)
def check(self, src, lineno, offset, end_lineno=None, end_offset=None, encoding='utf-8'):
with self.subTest(source=src, lineno=lineno, offset=offset):
with self.assertRaises(SyntaxError) as cm:
compile(src, '<fragment>', 'exec')
self.assertEqual(cm.exception.lineno, lineno)
self.assertEqual(cm.exception.offset, offset)
if end_lineno is not None:
self.assertEqual(cm.exception.end_lineno, end_lineno)
if end_offset is not None:
self.assertEqual(cm.exception.end_offset, end_offset)
if cm.exception.text is not None:
if not isinstance(src, str):
src = src.decode(encoding, 'replace')
line = src.split('\n')[lineno-1]
self.assertIn(line, cm.exception.text)
def test_error_offset_continuation_characters(self):
check = self.check
check('"\\\n"(1 for c in I,\\\n\\', 2, 2)
def testSyntaxErrorOffset(self):
check = self.check
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)
check(b'# -*- coding: cp1251 -*-\nPython = "\xcf\xb3\xf2\xee\xed" +',
2, 19, encoding='cp1251')
check(b'Python = "\xcf\xb3\xf2\xee\xed" +', 1, 10)
check('x = "a', 1, 5)
check('lambda x: x = 2', 1, 1)
check('f{a + b + c}', 1, 2)
check('[file for str(file) in []\n]', 1, 11)
check('a = « hello » « world »', 1, 5)
check('[\nfile\nfor str(file)\nin\n[]\n]', 3, 5)
check('[file for\n str(file) in []]', 2, 2)
check("ages = {'Alice'=22, 'Bob'=23}", 1, 9)
check('match ...:\n case {**rest, "key": value}:\n ...', 2, 19)
check("[a b c d e f]", 1, 2)
check("for x yfff:", 1, 7)
check("f(a for a in b, c)", 1, 3, 1, 15)
check("f(a for a in b if a, c)", 1, 3, 1, 20)
check("f(a, b for b in c)", 1, 6, 1, 18)
check("f(a, b for b in c, d)", 1, 6, 1, 18)
# Errors thrown by compile.c
check('class foo:return 1', 1, 11)
check('def f():\n continue', 2, 3)
check('def f():\n break', 2, 3)
check('try:\n pass\nexcept:\n pass\nexcept ValueError:\n pass', 3, 1)
check('try:\n pass\nexcept*:\n pass', 3, 8)
check('try:\n pass\nexcept*:\n pass\nexcept* ValueError:\n pass', 3, 8)
# Errors thrown by the tokenizer
check('(0x+1)', 1, 3)
check('x = 0xI', 1, 6)
check('0010 + 2', 1, 1)
check('x = 32e-+4', 1, 8)
check('x = 0o9', 1, 7)
check('\u03b1 = 0xI', 1, 6)
check(b'\xce\xb1 = 0xI', 1, 6)
check(b'# -*- coding: iso8859-7 -*-\n\xe1 = 0xI', 2, 6,
encoding='iso8859-7')
check(b"""if 1:
def foo():
'''
def bar():
pass
def baz():
'''quux'''
""", 9, 24)
check("pass\npass\npass\n(1+)\npass\npass\npass", 4, 4)
check("(1+)", 1, 4)
check("[interesting\nfoo()\n", 1, 1)
check(b"\xef\xbb\xbf#coding: utf8\nprint('\xe6\x88\x91')\n", 0, -1)
check("""f'''
{
(123_a)
}'''""", 3, 17)
check("""f'''
{
f\"\"\"
{
(123_a)
}
\"\"\"
}'''""", 5, 17)
check('''f"""
{
6
0="""''', 5, 13)
check('b"fooжжж"'.encode(), 1, 1, 1, 10)
# Errors thrown by symtable.c
check('x = [(yield i) for i in range(3)]', 1, 7)
check('def f():\n from _ import *', 2, 17)
check('def f(x, x):\n pass', 1, 10)
check('{i for i in range(5) if (j := 0) for j in range(5)}', 1, 38)
check('def f(x):\n nonlocal x', 2, 3)
check('def f(x):\n x = 1\n global x', 3, 3)
check('nonlocal x', 1, 1)
check('def f():\n global x\n nonlocal x', 2, 3)
# Errors thrown by future.c
check('from __future__ import doesnt_exist', 1, 24)
check('from __future__ import braces', 1, 24)
check('x=1\nfrom __future__ import division', 2, 1)
check('foo(1=2)', 1, 5)
check('def f():\n x, y: int', 2, 3)
check('[*x for x in xs]', 1, 2)
check('foo(x for x in range(10), 100)', 1, 5)
check('for 1 in []: pass', 1, 5)
check('(yield i) = 2', 1, 2)
check('def f(*):\n pass', 1, 7)
@unittest.skipIf(INT_MAX >= sys.maxsize, "Downcasting to int is safe for col_offset")
@support.requires_resource('cpu')
@support.bigmemtest(INT_MAX, memuse=2, dry_run=False)
def testMemoryErrorBigSource(self, size):
src = b"if True:\n%*s" % (size, b"pass")
with self.assertRaisesRegex(OverflowError, "Parser column offset overflow"):
compile(src, '<fragment>', 'exec')
@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
@unittest.skipIf(_testcapi is None, "requires _testcapi")
def test_capi1():
try:
_testcapi.raise_exception(BadException, 1)
except TypeError as err:
co = err.__traceback__.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")
@unittest.skipIf(_testcapi is None, "requires _testcapi")
def test_capi2():
try:
_testcapi.raise_exception(BadException, 0)
except RuntimeError as err:
tb = err.__traceback__.tb_next
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")
@unittest.skipIf(_testcapi is None, "requires _testcapi")
def test_capi3():
self.assertRaises(SystemError, _testcapi.raise_exception,
InvalidException, 1)
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,
'end_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,
'end_offset': None}),
(SyntaxError, ('msgStr', ('filenameStr', 'linenoStr', 'offsetStr',
'textStr', 'endLinenoStr', 'endOffsetStr')), {},
{'offset' : 'offsetStr', 'text' : 'textStr',
'args' : ('msgStr', ('filenameStr', 'linenoStr',
'offsetStr', 'textStr',
'endLinenoStr', 'endOffsetStr')),
'print_file_and_line' : None, 'msg' : 'msgStr',
'filename' : 'filenameStr', 'lineno' : 'linenoStr',
'end_lineno': 'endLinenoStr', 'end_offset': 'endOffsetStr'}),
(SyntaxError, ('msgStr', 'filenameStr', 'linenoStr', 'offsetStr',
'textStr', 'endLinenoStr', 'endOffsetStr',
'print_file_and_lineStr'), {},
{'text' : None,
'args' : ('msgStr', 'filenameStr', 'linenoStr', 'offsetStr',
'textStr', 'endLinenoStr', 'endOffsetStr',
'print_file_and_lineStr'),
'print_file_and_line' : None, 'msg' : 'msgStr',
'filename' : None, 'lineno' : None, 'offset' : None,
'end_lineno': None, 'end_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'}),
(AttributeError, ('foo',), dict(name='name', obj='obj'),
dict(args=('foo',), name='name', obj='obj')),
]
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, kwargs, expected in exceptionList:
try:
e = exc(*args, **kwargs)
except:
print(f"\nexc={exc!r}, args={args!r}", 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))
if exc == AttributeError and checkArgName == 'obj':
# See GH-103352, we're not pickling
# obj at this point. So verify it's None.
want = repr(None)
else:
want = repr(expected[checkArgName])
self.assertEqual(got, want,
'pickled "%r", attribute "%s' %
(e, checkArgName))
def test_setstate(self):
e = Exception(42)
e.blah = 53
self.assertEqual(e.args, (42,))
self.assertEqual(e.blah, 53)
self.assertRaises(AttributeError, getattr, e, 'a')
self.assertRaises(AttributeError, getattr, e, 'b')
e.__setstate__({'a': 1 , 'b': 2})
self.assertEqual(e.args, (42,))
self.assertEqual(e.blah, 53)
self.assertEqual(e.a, 1)
self.assertEqual(e.b, 2)
e.__setstate__({'a': 11, 'args': (1,2,3), 'blah': 35})
self.assertEqual(e.args, (1,2,3))
self.assertEqual(e.blah, 35)
self.assertEqual(e.a, 11)
self.assertEqual(e.b, 2)
def test_invalid_setstate(self):
e = Exception(42)
with self.assertRaisesRegex(TypeError, "state is not a dictionary"):
e.__setstate__(42)
def test_notes(self):
for e in [BaseException(1), Exception(2), ValueError(3)]:
with self.subTest(e=e):
self.assertFalse(hasattr(e, '__notes__'))
e.add_note("My Note")
self.assertEqual(e.__notes__, ["My Note"])
with self.assertRaises(TypeError):
e.add_note(42)
self.assertEqual(e.__notes__, ["My Note"])
e.add_note("Your Note")
self.assertEqual(e.__notes__, ["My Note", "Your Note"])
del e.__notes__
self.assertFalse(hasattr(e, '__notes__'))
e.add_note("Our Note")
self.assertEqual(e.__notes__, ["Our Note"])
e.__notes__ = 42
self.assertEqual(e.__notes__, 42)
with self.assertRaises(TypeError):
e.add_note("will not work")
self.assertEqual(e.__notes__, 42)
def testWithTraceback(self):
try:
raise IndexError(4)
except Exception as e:
tb = e.__traceback__
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 test_invalid_setattr(self):
TE = TypeError
exc = Exception()
msg = "'int' object is not iterable"
self.assertRaisesRegex(TE, msg, setattr, exc, 'args', 1)
msg = "__traceback__ must be a traceback or None"
self.assertRaisesRegex(TE, msg, setattr, exc, '__traceback__', 1)
msg = "exception cause must be None or derive from BaseException"
self.assertRaisesRegex(TE, msg, setattr, exc, '__cause__', 1)
msg = "exception context must be None or derive from BaseException"
self.assertRaisesRegex(TE, msg, setattr, exc, '__context__', 1)
def test_invalid_delattr(self):
TE = TypeError
try:
raise IndexError(4)
except Exception as e:
exc = e
msg = "may not be deleted"
self.assertRaisesRegex(TE, msg, delattr, exc, 'args')
self.assertRaisesRegex(TE, msg, delattr, exc, '__traceback__')
self.assertRaisesRegex(TE, msg, delattr, exc, '__cause__')
self.assertRaisesRegex(TE, msg, delattr, exc, '__context__')
def testNoneClearsTracebackAttr(self):
try:
raise IndexError(4)
except Exception as e:
tb = e.__traceback__
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 test_exception_cleanup_names(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.assertIsInstance(e, Exception)
self.assertNotIn('e', locals())
with self.assertRaises(UnboundLocalError):
e
def test_exception_cleanup_names2(self):
# Make sure the cleanup doesn't break if the variable is explicitly deleted.
try:
raise Exception()
except Exception as e:
self.assertIsInstance(e, Exception)
del e
self.assertNotIn('e', locals())
with self.assertRaises(UnboundLocalError):
e
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
gc_collect() # For PyPy or other GCs.
obj = wr()
self.assertIsNone(obj)
# Qualified "except" without "as"
obj = MyObj()
wr = weakref.ref(obj)
try:
inner_raising_func()
except MyException:
pass
obj = None
gc_collect() # For PyPy or other GCs.
obj = wr()
self.assertIsNone(obj)
# Bare "except"
obj = MyObj()
wr = weakref.ref(obj)
try:
inner_raising_func()
except:
pass
obj = None
gc_collect() # For PyPy or other GCs.
obj = wr()
self.assertIsNone(obj)
# "except" with premature block leave
obj = MyObj()
wr = weakref.ref(obj)
for i in [0]:
try:
inner_raising_func()
except:
break
obj = None
gc_collect() # For PyPy or other GCs.
obj = wr()
self.assertIsNone(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
gc_collect() # For PyPy or other GCs.
obj = wr()
# guarantee no ref cycles on CPython (don't gc_collect)
if check_impl_detail(cpython=False):
gc_collect()
self.assertIsNone(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.assertIsNone(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.assertIsNone(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.exception()
yield sys.exception()
yield sys.exception()
g = yield_raise()
self.assertIsInstance(next(g), KeyError)
self.assertIsNone(sys.exception())
self.assertIsInstance(next(g), KeyError)
self.assertIsNone(sys.exception())
self.assertIsNone(next(g))
# Same test, but inside an exception handler
try:
raise TypeError("foo")
except TypeError:
g = yield_raise()
self.assertIsInstance(next(g), KeyError)
self.assertIsInstance(sys.exception(), TypeError)
self.assertIsInstance(next(g), KeyError)
self.assertIsInstance(sys.exception(), TypeError)
self.assertIsInstance(next(g), TypeError)
del g
self.assertIsInstance(sys.exception(), 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.assertIsNone(sys.exception())
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.exception()
it = g()
next(it)
try:
1/0
except ZeroDivisionError as e:
self.assertIs(sys.exception(), e)
gen_exc = it.throw(e)
self.assertIs(sys.exception(), e)
self.assertIs(gen_exc, e)
self.assertIsNone(sys.exception())
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.exception()
raise
it = g()
try:
raise TypeError
except TypeError:
# The caller's exception state (TypeError) is temporarily
# saved in the generator.
tp = type(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.exception(), e)
# We used to find TypeError here.
self.assertIsNone(sys.exception())
def test_generator_doesnt_retain_old_exc(self):
def g():
self.assertIsInstance(sys.exception(), RuntimeError)
yield
self.assertIsNone(sys.exception())
it = g()
try:
raise RuntimeError
except RuntimeError:
next(it)
self.assertRaises(StopIteration, next, it)
def test_generator_finalizing_and_sys_exception(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.assertIsNone(sys.exception())
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
gc_collect() # For PyPy or other GCs.
obj = wr()
self.assertIsNone(obj)
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.exception()
e = ()
try:
raise Exception(MyObject())
except:
pass
gc_collect() # For PyPy or other GCs.
self.assertIsNone(e)
def test_raise_does_not_create_context_chain_cycle(self):
class A(Exception):
pass
class B(Exception):
pass
class C(Exception):
pass
# Create a context chain:
# C -> B -> A
# Then raise A in context of C.
try:
try:
raise A
except A as a_:
a = a_
try:
raise B
except B as b_:
b = b_
try:
raise C
except C as c_:
c = c_
self.assertIsInstance(a, A)
self.assertIsInstance(b, B)
self.assertIsInstance(c, C)
self.assertIsNone(a.__context__)
self.assertIs(b.__context__, a)
self.assertIs(c.__context__, b)
raise a
except A as e:
exc = e
# Expect A -> C -> B, without cycle
self.assertIs(exc, a)
self.assertIs(a.__context__, c)
self.assertIs(c.__context__, b)
self.assertIsNone(b.__context__)
def test_no_hang_on_context_chain_cycle1(self):
# See issue 25782. Cycle in context chain.
def cycle():
try:
raise ValueError(1)
except ValueError as ex:
ex.__context__ = ex
raise TypeError(2)
try:
cycle()
except Exception as e:
exc = e
self.assertIsInstance(exc, TypeError)
self.assertIsInstance(exc.__context__, ValueError)
self.assertIs(exc.__context__.__context__, exc.__context__)
def test_no_hang_on_context_chain_cycle2(self):
# See issue 25782. Cycle at head of context chain.
class A(Exception):
pass
class B(Exception):
pass
class C(Exception):
pass
# Context cycle:
# +-----------+
# V |
# C --> B --> A
with self.assertRaises(C) as cm:
try:
raise A()
except A as _a:
a = _a
try:
raise B()
except B as _b:
b = _b
try:
raise C()
except C as _c:
c = _c
a.__context__ = c
raise c
self.assertIs(cm.exception, c)
# Verify the expected context chain cycle
self.assertIs(c.__context__, b)
self.assertIs(b.__context__, a)
self.assertIs(a.__context__, c)
def test_no_hang_on_context_chain_cycle3(self):
# See issue 25782. Longer context chain with cycle.
class A(Exception):
pass
class B(Exception):
pass
class C(Exception):
pass
class D(Exception):
pass
class E(Exception):
pass
# Context cycle:
# +-----------+
# V |
# E --> D --> C --> B --> A
with self.assertRaises(E) as cm:
try:
raise A()
except A as _a:
a = _a
try:
raise B()
except B as _b:
b = _b
try:
raise C()
except C as _c:
c = _c
a.__context__ = c
try:
raise D()
except D as _d:
d = _d
e = E()
raise e
self.assertIs(cm.exception, e)
# Verify the expected context chain cycle
self.assertIs(e.__context__, d)
self.assertIs(d.__context__, c)
self.assertIs(c.__context__, b)
self.assertIs(b.__context__, a)
self.assertIs(a.__context__, c)
def test_context_of_exception_in_try_and_finally(self):
try:
try:
te = TypeError(1)
raise te
finally:
ve = ValueError(2)
raise ve
except Exception as e:
exc = e
self.assertIs(exc, ve)
self.assertIs(exc.__context__, te)
def test_context_of_exception_in_except_and_finally(self):
try:
try:
te = TypeError(1)
raise te
except:
ve = ValueError(2)
raise ve
finally:
oe = OSError(3)
raise oe
except Exception as e:
exc = e
self.assertIs(exc, oe)
self.assertIs(exc.__context__, ve)
self.assertIs(exc.__context__.__context__, te)
def test_context_of_exception_in_else_and_finally(self):
try:
try:
pass
except:
pass
else:
ve = ValueError(1)
raise ve
finally:
oe = OSError(2)
raise oe
except Exception as e:
exc = e
self.assertIs(exc, oe)
self.assertIs(exc.__context__, ve)
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)), "")
def test_unicode_error_str_does_not_crash(self):
# Test that str(UnicodeError(...)) does not crash.
# See https://github.com/python/cpython/issues/123378.
for start, end, objlen in product(
range(-5, 5),
range(-5, 5),
range(7),
):
obj = 'a' * objlen
with self.subTest('encode', objlen=objlen, start=start, end=end):
exc = UnicodeEncodeError('utf-8', obj, start, end, '')
self.assertIsInstance(str(exc), str)
with self.subTest('translate', objlen=objlen, start=start, end=end):
exc = UnicodeTranslateError(obj, start, end, '')
self.assertIsInstance(str(exc), str)
encoded = obj.encode()
with self.subTest('decode', objlen=objlen, start=start, end=end):
exc = UnicodeDecodeError('utf-8', encoded, start, end, '')
self.assertIsInstance(str(exc), str)
@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 as e:
return e
exc = g()
self.assertIsInstance(exc, RecursionError, type(exc))
self.assertIn("maximum recursion depth exceeded", str(exc))
@cpython_only
@support.requires_resource('cpu')
def test_trashcan_recursion(self):
# See bpo-33930
def foo():
o = object()
for x in range(1_000_000):
# Create a big chain of method objects that will trigger
# a deep chain of calls when they need to be destructed.
o = o.__dir__
foo()
support.gc_collect()
@cpython_only
def test_recursion_normalizing_exception(self):
import_module("_testinternalcapi")
# Issue #22898.
# Test that a RecursionError is raised when tstate->recursion_depth is
# equal to recursion_limit in PyErr_NormalizeException() and check
# that a ResourceWarning is printed.
# Prior to #22898, the recursivity of PyErr_NormalizeException() was
# controlled by tstate->recursion_depth and a PyExc_RecursionErrorInst
# singleton was being used in that case, that held traceback data and
# locals indefinitely and would cause a segfault in _PyExc_Fini() upon
# finalization of these locals.
code = """if 1:
import sys
from _testinternalcapi import get_recursion_depth
from test import support
class MyException(Exception): pass
def setrecursionlimit(depth):
while 1:
try:
sys.setrecursionlimit(depth)
return depth
except RecursionError:
# sys.setrecursionlimit() raises a RecursionError if
# the new recursion limit is too low (issue #25274).
depth += 1
def recurse(cnt):
cnt -= 1
if cnt:
recurse(cnt)
else:
generator.throw(MyException)
def gen():
f = open(%a, mode='rb', buffering=0)
yield
generator = gen()
next(generator)
recursionlimit = sys.getrecursionlimit()
try:
recurse(support.exceeds_recursion_limit())
finally:
sys.setrecursionlimit(recursionlimit)
print('Done.')
""" % __file__
rc, out, err = script_helper.assert_python_failure("-Wd", "-c", code)
# Check that the program does not fail with SIGABRT.
self.assertEqual(rc, 1)
self.assertIn(b'RecursionError', err)
self.assertIn(b'ResourceWarning', err)
self.assertIn(b'Done.', out)
@cpython_only
@unittest.skipIf(_testcapi is None, "requires _testcapi")
def test_recursion_normalizing_infinite_exception(self):
# Issue #30697. Test that a RecursionError is raised when
# maximum recursion depth has been exceeded when creating
# an exception
code = """if 1:
import _testcapi
try:
raise _testcapi.RecursingInfinitelyError
finally:
print('Done.')
"""
rc, out, err = script_helper.assert_python_failure("-c", code)
self.assertEqual(rc, 1)
expected = b'RecursionError: maximum recursion depth exceeded'
self.assertTrue(expected in err, msg=f"{expected!r} not found in {err[:3_000]!r}... (truncated)")
self.assertIn(b'Done.', out)
def test_recursion_in_except_handler(self):
def set_relative_recursion_limit(n):
depth = 1
while True:
try:
sys.setrecursionlimit(depth)
except RecursionError:
depth += 1
else:
break
sys.setrecursionlimit(depth+n)
def recurse_in_except():
try:
1/0
except:
recurse_in_except()
def recurse_after_except():
try:
1/0
except:
pass
recurse_after_except()
def recurse_in_body_and_except():
try:
recurse_in_body_and_except()
except:
recurse_in_body_and_except()
recursionlimit = sys.getrecursionlimit()
try:
set_relative_recursion_limit(10)
for func in (recurse_in_except, recurse_after_except, recurse_in_body_and_except):
with self.subTest(func=func):
try:
func()
except RecursionError:
pass
else:
self.fail("Should have raised a RecursionError")
finally:
sys.setrecursionlimit(recursionlimit)
@cpython_only
# Python built with Py_TRACE_REFS fail with a fatal error in
# _PyRefchain_Trace() on memory allocation error.
@unittest.skipIf(support.Py_TRACE_REFS, 'cannot test Py_TRACE_REFS build')
@unittest.skipIf(_testcapi is None, "requires _testcapi")
def test_recursion_normalizing_with_no_memory(self):
# Issue #30697. Test that in the abort that occurs when there is no
# memory left and the size of the Python frames stack is greater than
# the size of the list of preallocated MemoryError instances, the
# Fatal Python error message mentions MemoryError.
code = """if 1:
import _testcapi
class C(): pass
def recurse(cnt):
cnt -= 1
if cnt:
recurse(cnt)
else:
_testcapi.set_nomemory(0)
C()
recurse(16)
"""
with SuppressCrashReport():
rc, out, err = script_helper.assert_python_failure("-c", code)
self.assertIn(b'MemoryError', err)
@cpython_only
@unittest.skipIf(_testcapi is None, "requires _testcapi")
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 raised a MemoryError")
return traceback.format_tb(tb)
tb1 = raiseMemError()
tb2 = raiseMemError()
self.assertEqual(tb1, tb2)
@cpython_only
@unittest.skipIf(_testcapi is None, "requires _testcapi")
def test_exception_with_doc(self):
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
@unittest.skipIf(_testcapi is None, "requires _testcapi")
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")
gc_collect() # For PyPy or other GCs.
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")
gc_collect() # For PyPy or other GCs.
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
obj = BrokenDel()
with support.catch_unraisable_exception() as cm:
del obj
gc_collect() # For PyPy or other GCs.
self.assertEqual(cm.unraisable.object, BrokenDel.__del__)
self.assertIsNotNone(cm.unraisable.exc_traceback)
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"))
@cpython_only
# Python built with Py_TRACE_REFS fail with a fatal error in
# _PyRefchain_Trace() on memory allocation error.
@unittest.skipIf(support.Py_TRACE_REFS, 'cannot test Py_TRACE_REFS build')
@unittest.skipIf(_testcapi is None, "requires _testcapi")
def test_memory_error_in_PyErr_PrintEx(self):
code = """if 1:
import _testcapi
class C(): pass
_testcapi.set_nomemory(0, %d)
C()
"""
# Issue #30817: Abort in PyErr_PrintEx() when no memory.
# Span a large range of tests as the CPython code always evolves with
# changes that add or remove memory allocations.
for i in range(1, 20):
rc, out, err = script_helper.assert_python_failure("-c", code % i)
self.assertIn(rc, (1, 120))
self.assertIn(b'MemoryError', err)
def test_yield_in_nested_try_excepts(self):
#Issue #25612
class MainError(Exception):
pass
class SubError(Exception):
pass
def main():
try:
raise MainError()
except MainError:
try:
yield
except SubError:
pass
raise
coro = main()
coro.send(None)
with self.assertRaises(MainError):
coro.throw(SubError())
def test_generator_doesnt_retain_old_exc2(self):
#Issue 28884#msg282532
def g():
try:
raise ValueError
except ValueError:
yield 1
self.assertIsNone(sys.exception())
yield 2
gen = g()
try:
raise IndexError
except IndexError:
self.assertEqual(next(gen), 1)
self.assertEqual(next(gen), 2)
def test_raise_in_generator(self):
#Issue 25612#msg304117
def g():
yield 1
raise
yield 2
with self.assertRaises(ZeroDivisionError):
i = g()
try:
1/0
except:
next(i)
next(i)
@unittest.skipUnless(__debug__, "Won't work if __debug__ is False")
def test_assert_shadowing(self):
# Shadowing AssertionError would cause the assert statement to
# misbehave.
global AssertionError
AssertionError = TypeError
try:
assert False, 'hello'
except BaseException as e:
del AssertionError
self.assertIsInstance(e, AssertionError)
self.assertEqual(str(e), 'hello')
else:
del AssertionError
self.fail('Expected exception')
def test_memory_error_subclasses(self):
# bpo-41654: MemoryError instances use a freelist of objects that are
# linked using the 'dict' attribute when they are inactive/dead.
# Subclasses of MemoryError should not participate in the freelist
# schema. This test creates a MemoryError object and keeps it alive
# (therefore advancing the freelist) and then it creates and destroys a
# subclass object. Finally, it checks that creating a new MemoryError
# succeeds, proving that the freelist is not corrupted.
class TestException(MemoryError):
pass
try:
raise MemoryError
except MemoryError as exc:
inst = exc
try:
raise TestException
except Exception:
pass
for _ in range(10):
try:
raise MemoryError
except MemoryError as exc:
pass
gc_collect()
@unittest.skipIf(_testcapi is None, "requires _testcapi")
def test_memory_error_in_subinterp(self):
# gh-109894: subinterpreters shouldn't count on last resort memory error
# when MemoryError is raised through PyErr_NoMemory() call,
# and should preallocate memory errors as does the main interpreter.
# interp.static_objects.last_resort_memory_error.args
# should be initialized to empty tuple to avoid crash on attempt to print it.
code = f"""if 1:
import _testcapi
_testcapi.run_in_subinterp(\"[0]*{sys.maxsize}\")
exit(0)
"""
rc, _, err = script_helper.assert_python_ok("-c", code)
self.assertIn(b'MemoryError', err)
def test_keyerror_context(self):
# Make sure that _PyErr_SetKeyError() chains exceptions
try:
err1 = None
err2 = None
try:
d = {}
try:
raise ValueError("bug")
except Exception as exc:
err1 = exc
d[1]
except Exception as exc:
err2 = exc
self.assertIsInstance(err1, ValueError)
self.assertIsInstance(err2, KeyError)
self.assertEqual(err2.__context__, err1)
finally:
# Break any potential reference cycle
exc1 = None
exc2 = None
class NameErrorTests(unittest.TestCase):
def test_name_error_has_name(self):
try:
bluch
except NameError as exc:
self.assertEqual("bluch", exc.name)
def test_issue45826(self):
# regression test for bpo-45826
def f():
with self.assertRaisesRegex(NameError, 'aaa'):
aab
try:
f()
except self.failureException:
with support.captured_stderr() as err:
sys.__excepthook__(*sys.exc_info())
else:
self.fail("assertRaisesRegex should have failed.")
self.assertIn("aab", err.getvalue())
def test_issue45826_focused(self):
def f():
try:
nonsense
except BaseException as E:
E.with_traceback(None)
raise ZeroDivisionError()
try:
f()
except ZeroDivisionError:
with support.captured_stderr() as err:
sys.__excepthook__(*sys.exc_info())
self.assertIn("nonsense", err.getvalue())
self.assertIn("ZeroDivisionError", err.getvalue())
def test_gh_111654(self):
def f():
class TestClass:
TestClass
self.assertRaises(NameError, f)
# Note: name suggestion tests live in `test_traceback`.
class AttributeErrorTests(unittest.TestCase):
def test_attributes(self):
# Setting 'attr' should not be a problem.
exc = AttributeError('Ouch!')
self.assertIsNone(exc.name)
self.assertIsNone(exc.obj)
sentinel = object()
exc = AttributeError('Ouch', name='carry', obj=sentinel)
self.assertEqual(exc.name, 'carry')
self.assertIs(exc.obj, sentinel)
def test_getattr_has_name_and_obj(self):
class A:
blech = None
obj = A()
try:
obj.bluch
except AttributeError as exc:
self.assertEqual("bluch", exc.name)
self.assertEqual(obj, exc.obj)
try:
object.__getattribute__(obj, "bluch")
except AttributeError as exc:
self.assertEqual("bluch", exc.name)
self.assertEqual(obj, exc.obj)
def test_getattr_has_name_and_obj_for_method(self):
class A:
def blech(self):
return
obj = A()
try:
obj.bluch()
except AttributeError as exc:
self.assertEqual("bluch", exc.name)
self.assertEqual(obj, exc.obj)
# Note: name suggestion tests live in `test_traceback`.
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 = r"ImportError\(\) got an unexpected keyword argument 'invalid'"
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_reset_attributes(self):
exc = ImportError('test', name='name', path='path')
self.assertEqual(exc.args, ('test',))
self.assertEqual(exc.msg, 'test')
self.assertEqual(exc.name, 'name')
self.assertEqual(exc.path, 'path')
# Reset not specified attributes
exc.__init__()
self.assertEqual(exc.args, ())
self.assertEqual(exc.msg, None)
self.assertEqual(exc.name, None)
self.assertEqual(exc.path, None)
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)
def run_script(source):
if isinstance(source, str):
with open(TESTFN, 'w', encoding='utf-8') as testfile:
testfile.write(dedent(source))
else:
with open(TESTFN, 'wb') as testfile:
testfile.write(source)
_rc, _out, err = script_helper.assert_python_failure('-Wd', '-X', 'utf8', TESTFN)
return err.decode('utf-8').splitlines()
class AssertionErrorTests(unittest.TestCase):
def tearDown(self):
unlink(TESTFN)
@force_not_colorized
def test_assertion_error_location(self):
cases = [
('assert None',
[
' assert None',
' ^^^^',
'AssertionError',
],
),
('assert 0',
[
' assert 0',
' ^',
'AssertionError',
],
),
('assert 1 > 2',
[
' assert 1 > 2',
' ^^^^^',
'AssertionError',
],
),
('assert 1 > 2 and 3 > 2',
[
' assert 1 > 2 and 3 > 2',
' ^^^^^^^^^^^^^^^',
'AssertionError',
],
),
('assert 1 > 2, "messäge"',
[
' assert 1 > 2, "messäge"',
' ^^^^^',
'AssertionError: messäge',
],
),
('assert 1 > 2, "messäge"'.encode(),
[
' assert 1 > 2, "messäge"',
' ^^^^^',
'AssertionError: messäge',
],
),
('# coding: latin1\nassert 1 > 2, "messäge"'.encode('latin1'),
[
' assert 1 > 2, "messäge"',
' ^^^^^',
'AssertionError: messäge',
],
),
(BOM_UTF8 + 'assert 1 > 2, "messäge"'.encode(),
[
' assert 1 > 2, "messäge"',
' ^^^^^',
'AssertionError: messäge',
],
),
# Multiline:
("""
assert (
1 > 2)
""",
[
' 1 > 2)',
' ^^^^^',
'AssertionError',
],
),
("""
assert (
1 > 2), "Message"
""",
[
' 1 > 2), "Message"',
' ^^^^^',
'AssertionError: Message',
],
),
("""
assert (
1 > 2), \\
"Message"
""",
[
' 1 > 2), \\',
' ^^^^^',
'AssertionError: Message',
],
),
]
for source, expected in cases:
with self.subTest(source=source):
result = run_script(source)
self.assertEqual(result[-3:], expected)
@force_not_colorized
def test_multiline_not_highlighted(self):
cases = [
("""
assert (
1 > 2
)
""",
[
' 1 > 2',
'AssertionError',
],
),
("""
assert (
1 < 2 and
3 > 4
)
""",
[
' 1 < 2 and',
' 3 > 4',
'AssertionError',
],
),
]
for source, expected in cases:
with self.subTest(source=source):
result = run_script(source)
self.assertEqual(result[-len(expected):], expected)
class SyntaxErrorTests(unittest.TestCase):
maxDiff = None
@force_not_colorized
def test_range_of_offsets(self):
cases = [
# Basic range from 2->7
(("bad.py", 1, 2, "abcdefg", 1, 7),
dedent(
"""
File "bad.py", line 1
abcdefg
^^^^^
SyntaxError: bad bad
""")),
# end_offset = start_offset + 1
(("bad.py", 1, 2, "abcdefg", 1, 3),
dedent(
"""
File "bad.py", line 1
abcdefg
^
SyntaxError: bad bad
""")),
# Negative end offset
(("bad.py", 1, 2, "abcdefg", 1, -2),
dedent(
"""
File "bad.py", line 1
abcdefg
^
SyntaxError: bad bad
""")),
# end offset before starting offset
(("bad.py", 1, 4, "abcdefg", 1, 2),
dedent(
"""
File "bad.py", line 1
abcdefg
^
SyntaxError: bad bad
""")),
# Both offsets negative
(("bad.py", 1, -4, "abcdefg", 1, -2),
dedent(
"""
File "bad.py", line 1
abcdefg
SyntaxError: bad bad
""")),
# Both offsets negative and the end more negative
(("bad.py", 1, -4, "abcdefg", 1, -5),
dedent(
"""
File "bad.py", line 1
abcdefg
SyntaxError: bad bad
""")),
# Both offsets 0
(("bad.py", 1, 0, "abcdefg", 1, 0),
dedent(
"""
File "bad.py", line 1
abcdefg
SyntaxError: bad bad
""")),
# Start offset 0 and end offset not 0
(("bad.py", 1, 0, "abcdefg", 1, 5),
dedent(
"""
File "bad.py", line 1
abcdefg
SyntaxError: bad bad
""")),
# End offset pass the source length
(("bad.py", 1, 2, "abcdefg", 1, 100),
dedent(
"""
File "bad.py", line 1
abcdefg
^^^^^^
SyntaxError: bad bad
""")),
]
for args, expected in cases:
with self.subTest(args=args):
try:
raise SyntaxError("bad bad", args)
except SyntaxError as exc:
with support.captured_stderr() as err:
sys.__excepthook__(*sys.exc_info())
self.assertIn(expected, err.getvalue())
the_exception = exc
def test_encodings(self):
self.addCleanup(unlink, TESTFN)
source = (
'# -*- coding: cp437 -*-\n'
'"¢¢¢¢¢¢" + f(4, x for x in range(1))\n'
)
err = run_script(source.encode('cp437'))
self.assertEqual(err[-3], ' "¢¢¢¢¢¢" + f(4, x for x in range(1))')
self.assertEqual(err[-2], ' ^^^^^^^^^^^^^^^^^^^')
# Check backwards tokenizer errors
source = '# -*- coding: ascii -*-\n\n(\n'
err = run_script(source)
self.assertEqual(err[-3], ' (')
self.assertEqual(err[-2], ' ^')
def test_non_utf8(self):
# Check non utf-8 characters
self.addCleanup(unlink, TESTFN)
err = run_script(b"\x89")
self.assertIn("SyntaxError: Non-UTF-8 code starting with '\\x89' in file", err[-1])
def test_string_source(self):
def try_compile(source):
with self.assertRaises(SyntaxError) as cm:
compile(source, '<string>', 'exec')
return cm.exception
exc = try_compile('return "ä"')
self.assertEqual(str(exc), "'return' outside function (<string>, line 1)")
self.assertIsNone(exc.text)
self.assertEqual(exc.offset, 1)
self.assertEqual(exc.end_offset, 12)
exc = try_compile('return "ä"'.encode())
self.assertEqual(str(exc), "'return' outside function (<string>, line 1)")
self.assertIsNone(exc.text)
self.assertEqual(exc.offset, 1)
self.assertEqual(exc.end_offset, 12)
exc = try_compile(BOM_UTF8 + 'return "ä"'.encode())
self.assertEqual(str(exc), "'return' outside function (<string>, line 1)")
self.assertIsNone(exc.text)
self.assertEqual(exc.offset, 1)
self.assertEqual(exc.end_offset, 12)
exc = try_compile('# coding: latin1\nreturn "ä"'.encode('latin1'))
self.assertEqual(str(exc), "'return' outside function (<string>, line 2)")
self.assertIsNone(exc.text)
self.assertEqual(exc.offset, 1)
self.assertEqual(exc.end_offset, 12)
exc = try_compile('return "ä" #' + 'ä'*1000)
self.assertEqual(str(exc), "'return' outside function (<string>, line 1)")
self.assertIsNone(exc.text)
self.assertEqual(exc.offset, 1)
self.assertEqual(exc.end_offset, 12)
exc = try_compile('return "ä" # ' + 'ä'*1000)
self.assertEqual(str(exc), "'return' outside function (<string>, line 1)")
self.assertIsNone(exc.text)
self.assertEqual(exc.offset, 1)
self.assertEqual(exc.end_offset, 12)
def test_file_source(self):
self.addCleanup(unlink, TESTFN)
err = run_script('return "ä"')
self.assertEqual(err[-3:], [
' return "ä"',
' ^^^^^^^^^^',
"SyntaxError: 'return' outside function"])
err = run_script('return "ä"'.encode())
self.assertEqual(err[-3:], [
' return "ä"',
' ^^^^^^^^^^',
"SyntaxError: 'return' outside function"])
err = run_script(BOM_UTF8 + 'return "ä"'.encode())
self.assertEqual(err[-3:], [
' return "ä"',
' ^^^^^^^^^^',
"SyntaxError: 'return' outside function"])
err = run_script('# coding: latin1\nreturn "ä"'.encode('latin1'))
self.assertEqual(err[-3:], [
' return "ä"',
' ^^^^^^^^^^',
"SyntaxError: 'return' outside function"])
err = run_script('return "ä" #' + 'ä'*1000)
self.assertEqual(err[-2:], [
' ^^^^^^^^^^^',
"SyntaxError: 'return' outside function"])
self.assertEqual(err[-3][:100], ' return "ä" #' + 'ä'*84)
err = run_script('return "ä" # ' + 'ä'*1000)
self.assertEqual(err[-2:], [
' ^^^^^^^^^^^',
"SyntaxError: 'return' outside function"])
self.assertEqual(err[-3][:100], ' return "ä" # ' + 'ä'*83)
def test_attributes_new_constructor(self):
args = ("bad.py", 1, 2, "abcdefg", 1, 100)
the_exception = SyntaxError("bad bad", args)
filename, lineno, offset, error, end_lineno, end_offset = args
self.assertEqual(filename, the_exception.filename)
self.assertEqual(lineno, the_exception.lineno)
self.assertEqual(end_lineno, the_exception.end_lineno)
self.assertEqual(offset, the_exception.offset)
self.assertEqual(end_offset, the_exception.end_offset)
self.assertEqual(error, the_exception.text)
self.assertEqual("bad bad", the_exception.msg)
def test_attributes_old_constructor(self):
args = ("bad.py", 1, 2, "abcdefg")
the_exception = SyntaxError("bad bad", args)
filename, lineno, offset, error = args
self.assertEqual(filename, the_exception.filename)
self.assertEqual(lineno, the_exception.lineno)
self.assertEqual(None, the_exception.end_lineno)
self.assertEqual(offset, the_exception.offset)
self.assertEqual(None, the_exception.end_offset)
self.assertEqual(error, the_exception.text)
self.assertEqual("bad bad", the_exception.msg)
def test_incorrect_constructor(self):
args = ("bad.py", 1, 2)
self.assertRaises(TypeError, SyntaxError, "bad bad", args)
args = ("bad.py", 1, 2, 4, 5, 6, 7)
self.assertRaises(TypeError, SyntaxError, "bad bad", args)
args = ("bad.py", 1, 2, "abcdefg", 1)
self.assertRaises(TypeError, SyntaxError, "bad bad", args)
class TestInvalidExceptionMatcher(unittest.TestCase):
def test_except_star_invalid_exception_type(self):
with self.assertRaises(TypeError):
try:
raise ValueError
except 42:
pass
with self.assertRaises(TypeError):
try:
raise ValueError
except (ValueError, 42):
pass
class PEP626Tests(unittest.TestCase):
def lineno_after_raise(self, f, *expected):
try:
f()
except Exception as ex:
t = ex.__traceback__
else:
self.fail("No exception raised")
lines = []
t = t.tb_next # Skip this function
while t:
frame = t.tb_frame
lines.append(
None if frame.f_lineno is None else
frame.f_lineno-frame.f_code.co_firstlineno
)
t = t.tb_next
self.assertEqual(tuple(lines), expected)
def test_lineno_after_raise_simple(self):
def simple():
1/0
pass
self.lineno_after_raise(simple, 1)
def test_lineno_after_raise_in_except(self):
def in_except():
try:
1/0
except:
1/0
pass
self.lineno_after_raise(in_except, 4)
def test_lineno_after_other_except(self):
def other_except():
try:
1/0
except TypeError as ex:
pass
self.lineno_after_raise(other_except, 3)
def test_lineno_in_named_except(self):
def in_named_except():
try:
1/0
except Exception as ex:
1/0
pass
self.lineno_after_raise(in_named_except, 4)
def test_lineno_in_try(self):
def in_try():
try:
1/0
finally:
pass
self.lineno_after_raise(in_try, 4)
def test_lineno_in_finally_normal(self):
def in_finally_normal():
try:
pass
finally:
1/0
pass
self.lineno_after_raise(in_finally_normal, 4)
def test_lineno_in_finally_except(self):
def in_finally_except():
try:
1/0
finally:
1/0
pass
self.lineno_after_raise(in_finally_except, 4)
def test_lineno_after_with(self):
class Noop:
def __enter__(self):
return self
def __exit__(self, *args):
pass
def after_with():
with Noop():
1/0
pass
self.lineno_after_raise(after_with, 2)
def test_missing_lineno_shows_as_none(self):
def f():
1/0
self.lineno_after_raise(f, 1)
f.__code__ = f.__code__.replace(co_linetable=b'\xf8\xf8\xf8\xf9\xf8\xf8\xf8')
self.lineno_after_raise(f, None)
def test_lineno_after_raise_in_with_exit(self):
class ExitFails:
def __enter__(self):
return self
def __exit__(self, *args):
raise ValueError
def after_with():
with ExitFails():
1/0
self.lineno_after_raise(after_with, 1, 1)
if __name__ == '__main__':
unittest.main()
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