My Python 3 version:

from itertools import product

a = list(map(int, input().split()))
b = list(map(int, input().split()))

print(*product(a, b))

Time flies. Answered this 3 years ago just like yesterday...

About the unpack operator * in *product(a, b), please kindly refer to Expression lists|Python Documentation and it further refers to PEP 448 with clear examples. For dictionary, the unpacker operator is ** instead. Thanks for the great Python.

>>> print(*[1], *[2], 3)
1 2 3
>>> dict(**{'x': 1}, y=2, **{'z': 3})
{'x': 1, 'y': 2, 'z': 3}

The list function for a and b is excessive. Ihor_L's version is simpler.

Yes, the solution is pretty simple, but the Editorial answer is a paragon of readability. Unless the question asks for it, long one-line answers should be verboten.

Here is Python 3 solution from my HackerrankPractice repository:

from itertools import product
a = list(map(int, input().split()))
b = list(map(int, input().split()))
print(*list(product(a, b)))

Feel free to ask if you have any questions :)

100% working ,Simple and easy :-)

Here's in Python 3

from itertools import product
print(*product(list(map(int, input().split())), list(map(int, input().split()))))

In python 2:

from itertools import product
A = map(int,raw_input().split())
B = map(int,raw_input().split())
A.sort()
B.sort()

ans = [A,B]
AxB = list(product(*ans))

for i in AxB:
	print i,