isalpha, isspace, upper solution in Clear category for All Upper II by kkkkk
def is_all_upper(text: str) -> bool:
"""Return true if all letters in text are uppercase."""
all_chars = ''.join([c for c in text if c.isalpha() and not c.isspace()])
return bool(all_chars) and all_chars.upper() == all_chars
March 13, 2020