all Python 3Byte sequencesfunction

bytearray.islower

bytearray — is* checks

All cased bytes are lower-case.

Syntax

ba.islower(...)

Only ASCII letters carry case here, and a sequence with no letters at all — digits, punctuation, or empty — returns False. The consequence matters: islower() is not the negation of isupper(), since a digits-only sequence makes both False, so "not upper, therefore lower" is a broken inference.

Examples

print(bytearray(b'abc').islower())   # → True
print(bytearray(b'abc1!').islower())   # → True
print(bytearray(b'Abc').islower())   # → False
print(bytearray(b'123').islower())   # → False
print(bytearray(b'').islower())   # → False

See also

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