The isupper Method in Python: Checking if a String is Uppercase

Returns True or False, indicating whether a string contains only uppercase characters.

isupper()¶

Returns True if all characters in the string that can be cased are uppercase; otherwise, returns False.

'HELLO'.isupper()  # True
'Hello'.isupper()  # False
'123'.isupper()    # False
'!@#'.isupper()    # False
''.isupper()       # False