def mac_addr(addr):
    WHITELIST_CHARS = ":0123456789ABCDEF"
    addr = addr.upper().strip()
    addr = "".join(char for char in addr if char in WHITELIST_CHARS)
    return addr


def text_input(text, OVERWRITE_WHITELIST_CHARS=""):
    WHITELIST_CHARS = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789 _.-"

    if OVERWRITE_WHITELIST_CHARS:
        WHITELIST_CHARS = OVERWRITE_WHITELIST_CHARS

    if not isinstance(text, str):
        return ""

    return "".join([char for char in text if char in WHITELIST_CHARS])