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

Dirty way:

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

Nicer way (more configurable):

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

Extra Super Dirty way using the replace function:

def replace_and_shrink(t):
    '''For when you absolutely, positively hate the normal ways to do this.'''
    t = t.replace(' ', '_')
    if '__' not in t:
        return t
    t = t.replace('__', '_')
    return replace_and_shrink(t)