Itertools chain method explained

Itertools chain makes an iterator that returns elements from the first iterable until it is exhausted, then proceeds to the next iterable, until all of the iterables are exhausted.

#Goal: Chain iterables into 1 iterable
from itertools import chain

numbers1= [1, 2, 3]
numbers2 = range(4,8) #range excludes to index

for number in chain(numbers1, numbers2):
   print number

1
2
3
4
5
6
7