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# mode: run
# tag: generators, lambda
def genexpr():
"""
>>> genexpr()
[0, 2, 4, 6, 8]
"""
x = 'abc'
result = list( x*2 for x in range(5) )
assert x == 'abc' # don't leak
return result
def genexpr_if():
"""
>>> genexpr_if()
[0, 4, 8]
"""
x = 'abc'
result = list( x*2 for x in range(5) if x % 2 == 0 )
assert x == 'abc' # don't leak
return result
def genexpr_if_false():
"""
>>> genexpr_if_false()
[]
"""
x = 'abc'
result = list( x*2 for x in range(5) if False )
assert x == 'abc' # don't leak
return result
def genexpr_with_lambda():
"""
>>> genexpr_with_lambda()
[0, 4, 8]
"""
x = 'abc'
result = list( x*2 for x in range(5) if (lambda x:x % 2)(x) == 0 )
assert x == 'abc' # don't leak
return result
def genexpr_of_lambdas(int N):
"""
>>> [ (f(), g()) for f,g in genexpr_of_lambdas(5) ]
[(0, 0), (1, 2), (2, 4), (3, 6), (4, 8)]
"""
return ( ((lambda : x), (lambda : x*2)) for x in range(N) )
def genexpr_with_bool_binop(values):
"""
>>> values = [(1, 2, 3), (None, 4, None), (5, None, 6)]
>>> genexpr_with_bool_binop(values)
[(1, 2, 3), ('X', 4, 'X'), (5, 'X', 6)]
"""
# copied from CPython's test_itertools.py
return [tuple((e is None and 'X' or e) for e in t) for t in values]
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