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def gen():
yield 1
yield 2
yield 3
yield 4
def gen2():
yield -1
print((yield from gen()))
yield 10
yield 11
g = gen2()
print(next(g))
print(next(g))
g.close()
try:
print(next(g))
except StopIteration:
print("StopIteration")
# Now variation of same test, but with leaf generator
# swallowing GeneratorExit exception - its upstream gen
# generator should still receive one.
def gen3():
yield 1
try:
yield 2
except GeneratorExit:
print("leaf caught GeneratorExit and swallowed it")
return
yield 3
yield 4
def gen4():
yield -1
try:
print((yield from gen3()))
except GeneratorExit:
print("delegating caught GeneratorExit")
raise
yield 10
yield 11
g = gen4()
print(next(g))
print(next(g))
print(next(g))
g.close()
try:
print(next(g))
except StopIteration:
print("StopIteration")
# Yet another variation - leaf generator gets GeneratorExit,
# and reraises a new GeneratorExit. This still should close chain properly.
def gen5():
yield 1
try:
yield 2
except GeneratorExit:
print("leaf caught GeneratorExit and reraised GeneratorExit")
raise GeneratorExit(123)
yield 3
yield 4
def gen6():
yield -1
try:
print((yield from gen5()))
except GeneratorExit:
print("delegating caught GeneratorExit")
raise
yield 10
yield 11
g = gen6()
print(next(g))
print(next(g))
print(next(g))
g.close()
try:
print(next(g))
except StopIteration:
print("StopIteration")
# case where generator ignores the close request and yields instead
def gen7():
try:
yield 123
except GeneratorExit:
yield 456
g = gen7()
print(next(g))
try:
g.close()
except RuntimeError:
print('RuntimeError')
# case where close is propagated up to a built-in iterator
def gen8():
g = range(2)
yield from g
g = gen8()
print(next(g))
g.close()
# case with a user-defined close method
class Iter:
def __iter__(self):
return self
def __next__(self):
return 1
def close(self):
print('close')
def gen9():
yield from Iter()
g = gen9()
print(next(g))
g.close()
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