Python：复制列表并同时删除元素

Question

我是python的新手，我正在尝试创建一个没有特定元素的列表副本。这就是我现在这样做的方式：

oldList[1,23,4,3,5,345,4]
newList = oldList[:]
del newList[3]
doSomthingToList(newList)

我想知道是否有更好的方法来做到这一点，而不是复制列表然后删除两行中的元素？

Answer 1

使用list comprehension：

>>> oldList = [1,23,4,3,5,345,4]
>>> newList = [x for i, x in enumerate(oldList) if i != 3] # by index
>>> newList
[1, 23, 4, 5, 345, 4]

>>> newList = [x for x in oldList if x != 4] # by value
>>> newList
[1, 23, 3, 5, 345]

Answer 2

oldList[1,23,4,3,5,345,4]
newList = oldlist[:3] + oldList[4:]
doSomthingToList(newList)

Answer 3

尝试使用'切片'：

>>> oldList = [1, 2, 3, 4, 5]
>>> newList = oldList[:2] + [oldList[3:]
>>> newList
[1, 2, 4, 5]

Answer 4

考虑使用内置函数filter

oldList = [1, 2, 3, 4, 5]
newList = filter(lambda number: number != 3, oldList)

# newList == [1,2,4,5]

filter的参数是function, iterable。它将您赋予它的函数应用于iterable的每个元素，并返回函数返回True的元素列表。