How do I reverse an itertools.chain object?

Question

My function creates a chain of generators:

def bar(num):
    import itertools
    some_sequence = (x*1.5 for x in range(num))
    some_other_sequence = (x*2.6 fo         


        

Answer 1

In theory you can't because chained objects may even contain infinite sequences such as itertools.count(...).

You should try to reverse your generators/sequences or use reversed(iterable) for each sequence if applicable and then chain them together last-to-first. Of course this highly depends on your use case.