How do I replace multiple spaces with just one character?

Question

Here\'s my code so far:

input1 = input(\"Please enter a string: \")
newstring = input1.replace(\' \',\'_\')
print(newstring)

So if I put in

Answer 1

This pattern will replace any groups of whitespace with a single underscore

newstring = '_'.join(input1.split())

If you only want to replace spaces (not tab/newline/linefeed etc.) it's probably easier to use a regex

import re
newstring = re.sub(' +', '_', input1)