Check for camel case in Python

I would like to check if a string is a camel case or not (boolean). I am inclined to use a regex but any other elegant solution would work. I wrote a simple regex

(?:[A-Z])(?:[a-z])+(?:[A-Z])(?:[a-z])+

Would this be correct? Or am I missing something?

Edit

I would like to capture names in a collection of text documents of the format

McDowell
O'Connor
T.Kasting

Edit2

I have modified my regex based on the suggestion in the comments

(?:[A-Z])(?:S?)+(?:[A-Z])(?:[a-z])+

Answer

You could check if a string has both upper and lowercase.

def is_camel_case(s):
    return s != s.lower() and s != s.upper() and "_" not in s


tests = [
    "camel",
    "camelCase",
    "CamelCase",
    "CAMELCASE",
    "camelcase",
    "Camelcase",
    "Case",
    "camel_case",
]

for test in tests:
    print(test, is_camel_case(test))

Output:

camel False
camelCase True
CamelCase True
CAMELCASE False
camelcase False
Camelcase True
Case True
camel_case False