all Python 3Strings (str)function

str.islower

character checks

True if all cased characters are lowercase and there is at least one.

Syntax

s.islower()

Caseless characters — digits, spaces, punctuation — are simply ignored, so 'abc123' is True while '123' and '' are False: at least one cased letter is required. Hence a common bug: not s.islower() does not mean "contains uppercase", it is also true for a string of digits alone.

Examples

print('abc'.islower())    # → True
print('Abc'.islower())    # → False
print('abc123'.islower())  # → True

See also

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