Source: 📖 Effective Python item 8

How zip works

The zip function takes two or more iterables as arguments and yields tuples containing the next item from each iterable.

president = ('Obama', 'Trump')
term_beginning = (2012, 2016)

for name, year in zip(president, term_beginning):
	print(name, year)
	
>>>
Obama 2012
Trump 2016

zip will keep yielding tuples until any of the involved iterables have been exhausted, meaning it's output will be limited to the length of its shortest input.