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# -----------------
# yield statement
# -----------------
def gen():
if random.choice([0, 1]):
yield 1
else:
yield ""
gen_exe = gen()
#? int() str()
next(gen_exe)
#? int() str() list
next(gen_exe, list)
def gen_ret(value):
yield value
#? int()
next(gen_ret(1))
#? []
next(gen_ret()).
# generators evaluate to true if cast by bool.
a = ''
if gen_ret():
a = 3
#? int()
a
# -----------------
# generators should not be indexable
# -----------------
def get(param):
if random.choice([0, 1]):
yield 1
else:
yield ""
#? []
get()[0].
# -----------------
# __iter__
# -----------------
for a in get():
#? int() str()
a
class Get():
def __iter__(self):
if random.choice([0, 1]):
yield 1
else:
yield ""
b = []
for a in Get():
#? int() str()
a
b += [a]
#? list()
b
#? int() str()
b[0]
g = iter(Get())
#? int() str()
next(g)
g = iter([1.0])
#? float()
next(g)
# -----------------
# __next__
# -----------------
class Counter:
def __init__(self, low, high):
self.current = low
self.high = high
def __iter__(self):
return self
def next(self):
""" need to have both __next__ and next, because of py2/3 testing """
return self.__next__()
def __next__(self):
if self.current > self.high:
raise StopIteration
else:
self.current += 1
return self.current - 1
for c in Counter(3, 8):
#? int()
print c
# -----------------
# tuples
# -----------------
def gen():
if random.choice([0,1]):
yield 1, ""
else:
yield 2, 1.0
a, b = next(gen())
#? int()
a
#? str() float()
b
def simple():
if random.choice([0, 1]):
yield 1
else:
yield ""
a, b = simple()
#? int() str()
a
# For now this is ok.
#?
b
def simple2():
yield 1
yield ""
a, b = simple2()
#? int()
a
#? str()
b
# -----------------
# More complicated access
# -----------------
# `close` is a method wrapper.
#? ['__call__']
gen().close.__call__
#?
gen().throw()
#? ['co_consts']
gen().gi_code.co_consts
#? []
gen.gi_code.co_consts
# `send` is also a method wrapper.
#? ['__call__']
gen().send.__call__
#? tuple()
gen().send()
#?
gen()()
# -----------------
# yield from
# -----------------
# python >= 3.3
def yield_from():
yield from iter([1])
#? int()
next(yield_from())
def yield_from_multiple():
yield from iter([1])
yield str()
x, y = yield_from_multiple()
#? int()
x
#? str()
y
|
