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seungha-kim/generator_lazy_eval.py

Last active December 4, 2015 07:27
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Lazy evaluation of Python generator
Raw
generator_lazy_eval.py
foo = 1
# expected [1, 1, 1]
gen = (foo for i in range(3))
# but...
foo = 2
list(gen)
# result: [2, 2, 2]
Raw
generator_lazy_eval2.py
from itertools import chain
list(chain(*((print(a, b) for b in range(2)) for a in range(2))))
# expected :
# 0 0
# 0 1
# 1 0
# 1 1
# [None, None, None, None]
# result :
# 1 0
# 1 1
# 1 0
# 1 1
# [None, None, None, None]
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