import re


def is_sha(text):
    """
    To be considered a SHA, it must have at least one digit.

    >>> is_sha('f75a283')
    True
    >>> is_sha('decade')
    False
    >>> is_sha('facade')
    False
    >>> is_sha('deedeed')
    False
    >>> is_sha('d670460b4b4aece5915caf5c68d12f560a9fe3e4')
    True
    >>> is_sha('ad670460b4b4aece5915caf5c68d12f560a9fe3e4')
    False
    >>> is_sha('670460b4b4aece5915caf5c68d12f560a9fe3e4')
    True
    >>> is_sha('670460b4b4aece5915caf5c68d12f560a9fe3g4')
    False
    """

    valid_sha = bool(re.match(r'''^[a-f0-9]{5,40}$''', text))
    has_digit = bool(re.search(r'\d', text))
    return valid_sha and has_digit