all unique

2022-05-30.py

question = """

Write a function that determines if all the characters in a given string 
are unique. Can you do this without making any new variables? You choose 
if you want to include capitalization in your consideration for this one, 
as a fun challenge.

Example:

> allUnique('Cassidy')
> false

> allUnique('cat & dog')
> false

> allUnique('cat+dog')
> true

"""

def allUnique(string):
    u = {}
    for ch in string:
        if not ch in u:
            u[ch] = 0
        u[ch] += 1
    return len(u) == len(string)

print(allUnique('Cassidy'))
print(allUnique('cat & dog'))
print(allUnique('cat+dog'))