追加是一个破坏性操作（它会修改的地方，而不是返回一个新的列表清单） 。惯用的方式做的非破坏性相当于追加是

append is a destructive operation (it modifies the list in place instead of of returning a new list). The idiomatic way to do the non-destructive equivalent of append would be

l = [1,2,3]
print l + [4] # [1,2,3,4]
print l # [1,2,3]

要回答你的问题，我的猜测是，如果追加返回新修改的列表中，用户可能会认为这是无损的，即它们可以写$ C $ ç像

to answer your question, my guess is that if append returned the newly modified list, users might think that it was non-destructive, ie they might write code like

m = l.append("a")
n = l.append("b")

和期望 N 是 [1,2,3，B]