As in with out outer scope variables, how do you loop getting the first element forward with one var and another var for the last element backward with the same loop? Is there a function similar to enumerate that returns two vars
you could zip
one iterator and its reverse:
z = range(20,30)
for x,y in zip(z,reversed(z)):
print(x,y)
results in:
20 29
21 28
22 27
23 26
24 25
25 24
26 23
27 22
28 21
29 20
With generators, though, you have to force iteration into a list
since reverse
expects a sequence
TypeError: argument to reversed() must be a sequence
list
, tuple
or range
are OK.
g = (x for x in somefunc() if x > 0)
lst = list(g)
for x,y in zip(lst, reversed(lst)):
...
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