Returns size in bits of abi_type

def size_of_type(abi_type):
    """
    Returns size in bits of abi_type
    """
    if 'string' in abi_type:
        return None
    if 'byte' in abi_type:
        return None
    if '[' in abi_type:
        return None
    if abi_type == 'bool':
        return 8
    if abi_type == 'address':
        return 160
    return int(re.sub(r"\D", "", abi_type))