bytes.isupper()

bytes.isupper() bytearray.isupper()

Return true if there is at least one uppercase alphabetic ASCII character in the sequence and no lowercase ASCII characters, false otherwise.

For example:

>>> b'HELLO WORLD'.isupper()
True
>>> b'Hello world'.isupper()
False

Lowercase ASCII characters are those byte values in the sequence b'abcdefghijklmnopqrstuvwxyz'. Uppercase ASCII characters are those byte values in the sequence b'ABCDEFGHIJKLMNOPQRSTUVWXYZ'.