How can I pass an empty value to a string variable in the split() function?

Question

Python

There is this code in python:

mainstr = input()
main1, main2, main3 = mainstr.split(" ")

If you enter two values, it will give an error that you need to enter three values. How to make it possible to enter two values, and leave the third line empty?

Answer 1

main1, main2, *_ = mainstr.split(" ")