String index out of range

Im running a small piece of code to test something, but when i run it, it says line 14 string index out of range

name1 = input("Type the first name: ")
name2 = input("Type the second name: ")
names = name1 + name2
names = "".join([i for i in names if not i.isdigit()])
names = names.lower()
numberlst = []
alternatelst = []
savelst = []
i = 0
while i <= len(names):
  i = sum = i + 1

what have i done wrong?

this might help, check this out,

How To Handle Indexerror: String Index Out Of Range In Python - Python Guides.

cool your boots sir, I don’t even know you, why you would be thinking that way, I’m just helping here voluntarily

puts boots in the fridge

Check your loop limit - maybe print(i) inside the loop.