def toDecimal(value, base):
    if not isinstance(base, int):
        raise TypeError('base must be integral')
    if not 2 <= base <= 10:
        raise ValueError('must have 2 <= base <= 10')
    if not isinstance(value, str):
        raise TypeError('value must be a string')
    if len(value) == 0:
        raise ValueError('value must be nonempty')
    highDigit = str(base-1)
    for digit in value:
        if not '0' <= digit <= highDigit:
            raise ValueError('invalid digit for given base')

    return int(value, base)    # This should be successful