Vanity Plates - Python

Trying to solve the questions of CS50 Python course.

Stuck at one of the questions: https://cs50.harvard.edu/python/2022/psets/2/plates/

Solved everything, however the "no letter after numeral" part is very hard for me.

I cannot understand why my solution does not work. Any idea?

Please do not give different solution, I read several of them, I want to understand where is the error in my version.

def main():  
    plate = input("Plate: ").strip()
    if is_valid(plate):
        print("Valid")
    else:
        print("Invalid")

def is_valid(s):
# check for non-letters and non-numbers
    if not s.isalnum():
        return False
# check for correct length    
    if len(s) < 2 or len(s) > 6:
        return False
# check for correct first two characters    
    if s[0].isdigit() or s[1].isdigit():
        return False
# check for incorrect third character if there is any    
    if len(s) > 2 and s[2] == "0":
        return False
# check for errors in 4, 5, 6 length plate nemes:
# 1. no first numeral with "0" value
    i = 0
    while i < len(s):
        if s[i].isdigit():
            if s[i] == "0":
                return False
            else:
                break
        i += 1    
# 2. no letter after numeral
    for i in range(len(s)):
        if s[i].isdigit():
            if i < len(s)-1 and s[i+1:].isalpha():
                return False
# all possible errors checked
    return True
            
main()

It seems the s[i+1:].isalpha() part never executes.

All you need to do is remove the colon from that statement. Not necessary to check every character after a number, just the next character.

s[i+1].isalpha() works.