Python List数据打印后，更改List中的值报语法错误

number_list = [1,3,5,7,9]
mix = ["python","12"]
second_num = number_list[1]
one_number = mix[0]
print("one is {0} second is {1}".format(one_number, second_num)

mix[1] =  100
print(mix)

mix[1] = 100 报语法错误。如果注释掉打印语句则没有问题。