all Python 3Byte sequencesfunction

bytearray.isalnum

bytearray — is* checks

All bytes are ASCII letters/digits and non-empty.

Syntax

ba.isalnum(...)

The check is strictly ASCII: only A-Z, a-z count as letters and only 0-9 as digits, so any byte at 128 or above (Cyrillic in UTF-8, for instance) makes it False. Underscore, hyphen, dot and space fail too, so this is not a usable "safe filename or identifier" test — for that, spell out your own allowed set.

Examples

print(bytearray(b'abc123').isalnum())   # → True
print(bytearray(b'abc 123').isalnum())   # → False
print(bytearray(b'user_42').isalnum())   # → False
print(bytearray(b'').isalnum())   # → False
print(bytearray('привет'.encode()).isalnum())   # → False

See also

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