divide list ['a', 'b', 'c', '1', '2', '3'] into three separate list

def divide():
    string_list = ['a', 'b', 'c', '1', '2', '3']
    list_1 = []
    list_2 = []
    list_3 = []
    for item in string_list:
        if item.isalpha():
            list_1.append(item)
        elif item.isdigit():
            if int(item) % 2 == 0:
                list_2.append(item)
            elif int(item) % 2 ==1:
                list_3.append(item)
    return list_1, list_2, list_3

divide()