python list遍历问题

Question

请问大家为什么第一个number1_list不是偶数而是空数集呀？谢谢大家

number_list = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
element = None
number1_list = []
number2_list = []
while element in number_list:
    if element %2 == 0:
        number1_list.append(element)
print(number1_list)
for element in number_list:
    if element %2 == 0:
        number2_list.append(element)
print(number2_list)

Answer 1

while element in number_list:
    if element %2 == 0:
        number1_list.append(element)

此时element为none，所以while循环根本不会循环起来，根本里面没有执行
while的写法是

i=0
while i < len(number_list):
    element = number_list[i]
    if element %2 == 0:
        number1_list.append(element)
    i += 1