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2891 lines (2400 loc) · 77.1 KB
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import copy
import gc
import pickle
import sys
import doctest
import unittest
import weakref
import inspect
import textwrap
import types
from test import support
try:
import _testcapi
except ImportError:
_testcapi = None
# This tests to make sure that if a SIGINT arrives just before we send into a
# yield from chain, the KeyboardInterrupt is raised in the innermost
# generator (see bpo-30039).
@unittest.skipUnless(_testcapi is not None and
hasattr(_testcapi, "raise_SIGINT_then_send_None"),
"needs _testcapi.raise_SIGINT_then_send_None")
class SignalAndYieldFromTest(unittest.TestCase):
def generator1(self):
return (yield from self.generator2())
def generator2(self):
try:
yield
except KeyboardInterrupt:
return "PASSED"
else:
return "FAILED"
def test_raise_and_yield_from(self):
gen = self.generator1()
gen.send(None)
try:
_testcapi.raise_SIGINT_then_send_None(gen)
except BaseException as _exc:
exc = _exc
self.assertIs(type(exc), StopIteration)
self.assertEqual(exc.value, "PASSED")
class FinalizationTest(unittest.TestCase):
def test_frame_resurrect(self):
# A generator frame can be resurrected by a generator's finalization.
def gen():
nonlocal frame
try:
yield
finally:
frame = sys._getframe()
g = gen()
wr = weakref.ref(g)
next(g)
del g
support.gc_collect()
self.assertIs(wr(), None)
self.assertTrue(frame)
del frame
support.gc_collect()
def test_refcycle(self):
# A generator caught in a refcycle gets finalized anyway.
old_garbage = gc.garbage[:]
finalized = False
def gen():
nonlocal finalized
try:
g = yield
yield 1
finally:
finalized = True
g = gen()
next(g)
g.send(g)
self.assertGreaterEqual(sys.getrefcount(g), 2)
self.assertFalse(finalized)
del g
support.gc_collect()
self.assertTrue(finalized)
self.assertEqual(gc.garbage, old_garbage)
def test_lambda_generator(self):
# bpo-23192, gh-119897: Test that a lambda returning a generator behaves
# like the equivalent function
f = lambda: (yield 1)
self.assertIsInstance(f(), types.GeneratorType)
self.assertEqual(next(f()), 1)
def g(): return (yield 1)
# test 'yield from'
f2 = lambda: (yield from g())
def g2(): return (yield from g())
f3 = lambda: (yield from f())
def g3(): return (yield from f())
for gen_fun in (f, g, f2, g2, f3, g3):
gen = gen_fun()
self.assertEqual(next(gen), 1)
with self.assertRaises(StopIteration) as cm:
gen.send(2)
self.assertEqual(cm.exception.value, 2)
def test_generator_resurrect(self):
# Test that a resurrected generator still has a valid gi_code
resurrected = []
# Resurrect a generator in a finalizer
exec(textwrap.dedent("""
def gen():
try:
yield
except:
resurrected.append(g)
g = gen()
next(g)
"""), {"resurrected": resurrected})
support.gc_collect()
self.assertEqual(len(resurrected), 1)
self.assertIsInstance(resurrected[0].gi_code, types.CodeType)
@unittest.expectedFailure # TODO: RUSTPYTHON; AssertionError: <frame object at 0xb4000073269f09e0> is not None
def test_exhausted_generator_frame_cycle(self):
def g():
yield
generator = g()
frame = generator.gi_frame
self.assertIsNone(frame.f_back)
next(generator)
self.assertIsNone(frame.f_back)
next(generator, None)
self.assertIsNone(frame.f_back)
class GeneratorTest(unittest.TestCase):
def test_name(self):
def func():
yield 1
# check generator names
gen = func()
self.assertEqual(gen.__name__, "func")
self.assertEqual(gen.__qualname__,
"GeneratorTest.test_name.<locals>.func")
# modify generator names
gen.__name__ = "name"
gen.__qualname__ = "qualname"
self.assertEqual(gen.__name__, "name")
self.assertEqual(gen.__qualname__, "qualname")
# generator names must be a string and cannot be deleted
self.assertRaises(TypeError, setattr, gen, '__name__', 123)
self.assertRaises(TypeError, setattr, gen, '__qualname__', 123)
self.assertRaises(TypeError, delattr, gen, '__name__')
self.assertRaises(TypeError, delattr, gen, '__qualname__')
# modify names of the function creating the generator
func.__qualname__ = "func_qualname"
func.__name__ = "func_name"
gen = func()
self.assertEqual(gen.__name__, "func_name")
self.assertEqual(gen.__qualname__, "func_qualname")
# unnamed generator
gen = (x for x in range(10))
self.assertEqual(gen.__name__,
"<genexpr>")
self.assertEqual(gen.__qualname__,
"GeneratorTest.test_name.<locals>.<genexpr>")
def test_copy(self):
def f():
yield 1
g = f()
with self.assertRaises(TypeError):
copy.copy(g)
def test_pickle(self):
def f():
yield 1
g = f()
for proto in range(pickle.HIGHEST_PROTOCOL + 1):
with self.assertRaises((TypeError, pickle.PicklingError)):
pickle.dumps(g, proto)
def test_send_non_none_to_new_gen(self):
def f():
yield 1
g = f()
with self.assertRaises(TypeError):
g.send(0)
self.assertEqual(next(g), 1)
def test_handle_frame_object_in_creation(self):
#Attempt to expose partially constructed frames
#See https://github.com/python/cpython/issues/94262
def cb(*args):
inspect.stack()
def gen():
yield 1
thresholds = gc.get_threshold()
gc.callbacks.append(cb)
gc.set_threshold(1, 0, 0)
try:
gen()
finally:
gc.set_threshold(*thresholds)
gc.callbacks.pop()
class Sneaky:
def __del__(self):
inspect.stack()
sneaky = Sneaky()
sneaky._s = Sneaky()
sneaky._s._s = sneaky
gc.set_threshold(1, 0, 0)
try:
del sneaky
gen()
finally:
gc.set_threshold(*thresholds)
def test_ag_frame_f_back(self):
async def f():
yield
ag = f()
self.assertIsNone(ag.ag_frame.f_back)
def test_cr_frame_f_back(self):
async def f():
pass
cr = f()
self.assertIsNone(cr.cr_frame.f_back)
cr.close() # Suppress RuntimeWarning.
def test_gi_frame_f_back(self):
def f():
yield
gi = f()
self.assertIsNone(gi.gi_frame.f_back)
def test_issue103488(self):
def gen_raises():
yield
raise ValueError()
def loop():
try:
for _ in gen_raises():
if True is False:
return
except ValueError:
pass
#This should not raise
loop()
def test_genexpr_only_calls_dunder_iter_once(self):
class Iterator:
def __init__(self):
self.val = 0
def __next__(self):
if self.val == 2:
raise StopIteration
self.val += 1
return self.val
# No __iter__ method
class C:
def __iter__(self):
return Iterator()
self.assertEqual([1, 2], list(i for i in C()))
@unittest.expectedFailure # TODO: RUSTPYTHON; AssertionError: False is not true
def test_close_clears_frame(self):
# gh-142766: Test that closing a generator clears its frame
class DetectDelete:
def __init__(self):
DetectDelete.deleted = False
def __del__(self):
DetectDelete.deleted = True
def generator(arg):
yield
# Test a freshly created generator (not suspended)
g = generator(DetectDelete())
g.close()
self.assertTrue(DetectDelete.deleted)
# Test a suspended generator
g = generator(DetectDelete())
next(g)
g.close()
self.assertTrue(DetectDelete.deleted)
# Clear via gi_frame.clear()
g = generator(DetectDelete())
g.gi_frame.clear()
self.assertTrue(DetectDelete.deleted)
class ModifyUnderlyingIterableTest(unittest.TestCase):
iterables = [
range(0),
range(20),
[1, 2, 3],
(2,),
{13, 48, 211},
frozenset((15, 8, 6)),
{1: 2, 3: 4},
]
non_iterables = [
None,
42,
3.0,
2j,
]
def genexpr(self):
return (x for x in range(10))
def genfunc(self):
def gen(it):
for x in it:
yield x
return gen(range(10))
def process_tests(self, get_generator, is_expr):
err_iterator = "'.*' object is not an iterator"
err_iterable = "'.*' object is not iterable"
for obj in self.iterables:
g_obj = get_generator(obj)
with self.subTest(g_obj=g_obj, obj=obj):
if is_expr:
self.assertRaisesRegex(TypeError, err_iterator, list, g_obj)
else:
self.assertListEqual(list(g_obj), list(obj))
g_iter = get_generator(iter(obj))
with self.subTest(g_iter=g_iter, obj=obj):
self.assertListEqual(list(g_iter), list(obj))
for obj in self.non_iterables:
g_obj = get_generator(obj)
with self.subTest(g_obj=g_obj):
err = err_iterator if is_expr else err_iterable
self.assertRaisesRegex(TypeError, err, list, g_obj)
def test_modify_f_locals(self):
def modify_f_locals(g, local, obj):
g.gi_frame.f_locals[local] = obj
return g
def get_generator_genexpr(obj):
return modify_f_locals(self.genexpr(), '.0', obj)
def get_generator_genfunc(obj):
return modify_f_locals(self.genfunc(), 'it', obj)
self.process_tests(get_generator_genexpr, True)
self.process_tests(get_generator_genfunc, False)
def test_new_gen_from_gi_code(self):
def new_gen_from_gi_code(g, obj):
generator_func = types.FunctionType(g.gi_code, {})
return generator_func(obj)
def get_generator_genexpr(obj):
return new_gen_from_gi_code(self.genexpr(), obj)
def get_generator_genfunc(obj):
return new_gen_from_gi_code(self.genfunc(), obj)
self.process_tests(get_generator_genexpr, True)
self.process_tests(get_generator_genfunc, False)
class ExceptionTest(unittest.TestCase):
# Tests for the issue #23353: check that the currently handled exception
# is correctly saved/restored in PyEval_EvalFrameEx().
def test_except_throw(self):
def store_raise_exc_generator():
try:
self.assertIsNone(sys.exception())
yield
except Exception as exc:
# exception raised by gen.throw(exc)
self.assertIsInstance(sys.exception(), ValueError)
self.assertIsNone(exc.__context__)
yield
# ensure that the exception is not lost
self.assertIsInstance(sys.exception(), ValueError)
yield
# we should be able to raise back the ValueError
raise
make = store_raise_exc_generator()
next(make)
try:
raise ValueError()
except Exception as exc:
try:
make.throw(exc)
except Exception:
pass
next(make)
with self.assertRaises(ValueError) as cm:
next(make)
self.assertIsNone(cm.exception.__context__)
self.assertIsNone(sys.exception())
def test_except_next(self):
def gen():
self.assertIsInstance(sys.exception(), ValueError)
yield "done"
g = gen()
try:
raise ValueError
except Exception:
self.assertEqual(next(g), "done")
self.assertIsNone(sys.exception())
def test_except_gen_except(self):
def gen():
try:
self.assertIsNone(sys.exception())
yield
# we are called from "except ValueError:", TypeError must
# inherit ValueError in its context
raise TypeError()
except TypeError as exc:
self.assertIsInstance(sys.exception(), TypeError)
self.assertEqual(type(exc.__context__), ValueError)
# here we are still called from the "except ValueError:"
self.assertIsInstance(sys.exception(), ValueError)
yield
self.assertIsNone(sys.exception())
yield "done"
g = gen()
next(g)
try:
raise ValueError
except Exception:
next(g)
self.assertEqual(next(g), "done")
self.assertIsNone(sys.exception())
def test_nested_gen_except_loop(self):
def gen():
for i in range(100):
self.assertIsInstance(sys.exception(), TypeError)
yield "doing"
def outer():
try:
raise TypeError
except:
for x in gen():
yield x
try:
raise ValueError
except Exception:
for x in outer():
self.assertEqual(x, "doing")
self.assertEqual(sys.exception(), None)
def test_except_throw_exception_context(self):
def gen():
try:
try:
self.assertIsNone(sys.exception())
yield
except ValueError:
# we are called from "except ValueError:"
self.assertIsInstance(sys.exception(), ValueError)
raise TypeError()
except Exception as exc:
self.assertIsInstance(sys.exception(), TypeError)
self.assertEqual(type(exc.__context__), ValueError)
# we are still called from "except ValueError:"
self.assertIsInstance(sys.exception(), ValueError)
yield
self.assertIsNone(sys.exception())
yield "done"
g = gen()
next(g)
try:
raise ValueError
except Exception as exc:
g.throw(exc)
self.assertEqual(next(g), "done")
self.assertIsNone(sys.exception())
def test_except_throw_bad_exception(self):
class E(Exception):
def __new__(cls, *args, **kwargs):
return cls
def boring_generator():
yield
gen = boring_generator()
err_msg = 'should have returned an instance of BaseException'
with self.assertRaisesRegex(TypeError, err_msg):
gen.throw(E)
self.assertRaises(StopIteration, next, gen)
def generator():
with self.assertRaisesRegex(TypeError, err_msg):
yield
gen = generator()
next(gen)
with self.assertRaises(StopIteration):
gen.throw(E)
def test_gen_3_arg_deprecation_warning(self):
def g():
yield 42
gen = g()
with self.assertWarns(DeprecationWarning):
with self.assertRaises(TypeError):
gen.throw(TypeError, TypeError(24), None)
def test_stopiteration_error(self):
# See also PEP 479.
def gen():
raise StopIteration
yield
with self.assertRaisesRegex(RuntimeError, 'raised StopIteration'):
next(gen())
def test_tutorial_stopiteration(self):
# Raise StopIteration" stops the generator too:
def f():
yield 1
raise StopIteration
yield 2 # never reached
g = f()
self.assertEqual(next(g), 1)
with self.assertRaisesRegex(RuntimeError, 'raised StopIteration'):
next(g)
def test_return_tuple(self):
def g():
return (yield 1)
gen = g()
self.assertEqual(next(gen), 1)
with self.assertRaises(StopIteration) as cm:
gen.send((2,))
self.assertEqual(cm.exception.value, (2,))
def test_return_stopiteration(self):
def g():
return (yield 1)
gen = g()
self.assertEqual(next(gen), 1)
with self.assertRaises(StopIteration) as cm:
gen.send(StopIteration(2))
self.assertIsInstance(cm.exception.value, StopIteration)
self.assertEqual(cm.exception.value.value, 2)
class GeneratorCloseTest(unittest.TestCase):
def test_close_no_return_value(self):
def f():
yield
gen = f()
gen.send(None)
self.assertIsNone(gen.close())
def test_close_return_value(self):
def f():
try:
yield
# close() raises GeneratorExit here, which is caught
except GeneratorExit:
return 0
gen = f()
gen.send(None)
self.assertEqual(gen.close(), 0)
def test_close_not_catching_exit(self):
def f():
yield
# close() raises GeneratorExit here, which isn't caught and
# therefore propagates -- no return value
return 0
gen = f()
gen.send(None)
self.assertIsNone(gen.close())
def test_close_not_started(self):
def f():
try:
yield
except GeneratorExit:
return 0
gen = f()
self.assertIsNone(gen.close())
def test_close_exhausted(self):
def f():
try:
yield
except GeneratorExit:
return 0
gen = f()
next(gen)
with self.assertRaises(StopIteration):
next(gen)
self.assertIsNone(gen.close())
def test_close_closed(self):
def f():
try:
yield
except GeneratorExit:
return 0
gen = f()
gen.send(None)
self.assertEqual(gen.close(), 0)
self.assertIsNone(gen.close())
def test_close_raises(self):
def f():
try:
yield
except GeneratorExit:
pass
raise RuntimeError
gen = f()
gen.send(None)
with self.assertRaises(RuntimeError):
gen.close()
def test_close_releases_frame_locals(self):
# See gh-118272
class Foo:
pass
f = Foo()
f_wr = weakref.ref(f)
def genfn():
a = f
yield
g = genfn()
next(g)
del f
g.close()
support.gc_collect()
self.assertIsNone(f_wr())
# See https://github.com/python/cpython/issues/125723
class GeneratorDeallocTest(unittest.TestCase):
@unittest.expectedFailure # TODO: RUSTPYTHON; frame uses shared Arc, no ownership transfer
def test_frame_outlives_generator(self):
def g1():
a = 42
yield sys._getframe()
def g2():
a = 42
yield
def g3(obj):
a = 42
obj.frame = sys._getframe()
yield
class ObjectWithFrame():
def __init__(self):
self.frame = None
def get_frame(index):
if index == 1:
return next(g1())
elif index == 2:
gen = g2()
next(gen)
return gen.gi_frame
elif index == 3:
obj = ObjectWithFrame()
next(g3(obj))
return obj.frame
else:
return None
for index in (1, 2, 3):
with self.subTest(index=index):
frame = get_frame(index)
frame_locals = frame.f_locals
self.assertIn('a', frame_locals)
self.assertEqual(frame_locals['a'], 42)
@unittest.expectedFailure # TODO: RUSTPYTHON; frame locals don't survive generator deallocation
def test_frame_locals_outlive_generator(self):
frame_locals1 = None
def g1():
nonlocal frame_locals1
frame_locals1 = sys._getframe().f_locals
a = 42
yield
def g2():
a = 42
yield sys._getframe().f_locals
def get_frame_locals(index):
if index == 1:
nonlocal frame_locals1
next(g1())
return frame_locals1
if index == 2:
return next(g2())
else:
return None
for index in (1, 2):
with self.subTest(index=index):
frame_locals = get_frame_locals(index)
self.assertIn('a', frame_locals)
self.assertEqual(frame_locals['a'], 42)
def test_frame_locals_outlive_generator_with_exec(self):
def g():
a = 42
yield locals(), sys._getframe().f_locals
locals_ = {'g': g}
for i in range(10):
exec("snapshot, live_locals = next(g())", locals=locals_)
for l in (locals_['snapshot'], locals_['live_locals']):
self.assertIn('a', l)
self.assertEqual(l['a'], 42)
class GeneratorThrowTest(unittest.TestCase):
def test_exception_context_with_yield(self):
def f():
try:
raise KeyError('a')
except Exception:
yield
gen = f()
gen.send(None)
with self.assertRaises(ValueError) as cm:
gen.throw(ValueError)
context = cm.exception.__context__
self.assertEqual((type(context), context.args), (KeyError, ('a',)))
def test_exception_context_with_yield_inside_generator(self):
# Check that the context is also available from inside the generator
# with yield, as opposed to outside.
def f():
try:
raise KeyError('a')
except Exception:
try:
yield
except Exception as exc:
self.assertEqual(type(exc), ValueError)
context = exc.__context__
self.assertEqual((type(context), context.args),
(KeyError, ('a',)))
yield 'b'
gen = f()
gen.send(None)
actual = gen.throw(ValueError)
# This ensures that the assertions inside were executed.
self.assertEqual(actual, 'b')
def test_exception_context_with_yield_from(self):
def f():
yield
def g():
try:
raise KeyError('a')
except Exception:
yield from f()
gen = g()
gen.send(None)
with self.assertRaises(ValueError) as cm:
gen.throw(ValueError)
context = cm.exception.__context__
self.assertEqual((type(context), context.args), (KeyError, ('a',)))
def test_exception_context_with_yield_from_with_context_cycle(self):
# Check trying to create an exception context cycle:
# https://bugs.python.org/issue40696
has_cycle = None
def f():
yield
def g(exc):
nonlocal has_cycle
try:
raise exc
except Exception:
try:
yield from f()
except Exception as exc:
has_cycle = (exc is exc.__context__)
yield
exc = KeyError('a')
gen = g(exc)
gen.send(None)
gen.throw(exc)
# This also distinguishes from the initial has_cycle=None.
self.assertEqual(has_cycle, False)
def test_throw_after_none_exc_type(self):
def g():
try:
raise KeyError
except KeyError:
pass
try:
yield
except Exception:
raise RuntimeError
gen = g()
gen.send(None)
with self.assertRaises(RuntimeError) as cm:
gen.throw(ValueError)
class GeneratorStackTraceTest(unittest.TestCase):
def check_stack_names(self, frame, expected):
names = []
while frame:
name = frame.f_code.co_name
# Stop checking frames when we get to our test helper.
if (name.startswith('check_') or name.startswith('call_')
or name.startswith('test')):
break
names.append(name)
frame = frame.f_back
self.assertEqual(names, expected)
def check_yield_from_example(self, call_method):
def f():
self.check_stack_names(sys._getframe(), ['f', 'g'])
try:
yield
except Exception:
pass
self.check_stack_names(sys._getframe(), ['f', 'g'])
def g():
self.check_stack_names(sys._getframe(), ['g'])
yield from f()
self.check_stack_names(sys._getframe(), ['g'])
gen = g()
gen.send(None)
try:
call_method(gen)
except StopIteration:
pass
def test_send_with_yield_from(self):
def call_send(gen):
gen.send(None)
self.check_yield_from_example(call_send)
def test_throw_with_yield_from(self):
def call_throw(gen):
gen.throw(RuntimeError)
self.check_yield_from_example(call_throw)
def test_throw_with_yield_from_custom_generator(self):
class CustomGen:
def __init__(self, test):
self.test = test
def throw(self, *args):
self.test.check_stack_names(sys._getframe(), ['throw', 'g'])
def __iter__(self):
return self
def __next__(self):
return 42
def g(target):
yield from target
gen = g(CustomGen(self))
gen.send(None)
gen.throw(RuntimeError)
class YieldFromTests(unittest.TestCase):
def test_generator_gi_yieldfrom(self):
def a():
self.assertEqual(inspect.getgeneratorstate(gen_b), inspect.GEN_RUNNING)
self.assertIsNone(gen_b.gi_yieldfrom)
yield
self.assertEqual(inspect.getgeneratorstate(gen_b), inspect.GEN_RUNNING)
self.assertIsNone(gen_b.gi_yieldfrom)
def b():
self.assertIsNone(gen_b.gi_yieldfrom)
yield from a()
self.assertIsNone(gen_b.gi_yieldfrom)
yield
self.assertIsNone(gen_b.gi_yieldfrom)
gen_b = b()
self.assertEqual(inspect.getgeneratorstate(gen_b), inspect.GEN_CREATED)
self.assertIsNone(gen_b.gi_yieldfrom)
gen_b.send(None)
self.assertEqual(inspect.getgeneratorstate(gen_b), inspect.GEN_SUSPENDED)
self.assertEqual(gen_b.gi_yieldfrom.gi_code.co_name, 'a')
gen_b.send(None)