list1 = ["a", "b", "c"]
list2 = list1.append("d")
print(list2)
这个输出没有。不知道为什么?
list3 = ["a", "b", "c"]
list3.append("d")
list4 = list3
print(list4)
这是正确的,并输出[a','b','c','d']
你必须这样做:
list1 = ["a", "b", "c"]
list1.append("d")
list2 = list1
print(list2)
This answer explains why very well:
https://stackoverflow.com/questions/20016802/why-does-list-append-return-none/#answer-20016976