Pythonic way to emulate itertools.product in python 2.4
I have a python 3 script that uses itertools.product
, but I need to be able to run it on a machine that only has python 2.4 installed. Since itertools.product
is new in python 2.6, I no longer have access to this function.
How can I emulate itertools.product
in Python 2.4 i开发者_开发百科n a pythonic way?
Equivalent code from http://docs.python.org/library/itertools.html#itertools.product
def product(*args, **kwds):
# product('ABCD', 'xy') --> Ax Ay Bx By Cx Cy Dx Dy
# product(range(2), repeat=3) --> 000 001 010 011 100 101 110 111
pools = map(tuple, args) * kwds.get('repeat', 1)
result = [[]]
for pool in pools:
result = [x+[y] for x in result for y in pool]
for prod in result:
yield tuple(prod)
I'm not too familiar with python 2.4, but per the 2.7 docs:
This function is equivalent to the following code, except that the actual implementation does not build up intermediate results in memory:
def product(*args, **kwds):
# product('ABCD', 'xy') --> Ax Ay Bx By Cx Cy Dx Dy
# product(range(2), repeat=3) --> 000 001 010 011 100 101 110 111
pools = map(tuple, args) * kwds.get('repeat', 1)
result = [[]]
for pool in pools:
result = [x+[y] for x in result for y in pool]
for prod in result:
yield tuple(prod)
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