在python中将一个列表插入另一个列表的语法是什么?

问题:在python中将一个列表插入另一个列表的语法是什么?

给出两个列表:

x = [1,2,3]
y = [4,5,6]

语法是什么:

  1. 插入xy这样y现在看起来像[1, 2, 3, [4, 5, 6]]
  2. 将所有项目x插入y,使y现在看起来像[1, 2, 3, 4, 5, 6]

Given two lists:

x = [1,2,3]
y = [4,5,6]

What is the syntax to:

  1. Insert x into y such that y now looks like [1, 2, 3, [4, 5, 6]]?
  2. Insert all the items of x into y such that y now looks like [1, 2, 3, 4, 5, 6]?

回答 0

你是说append

>>> x = [1,2,3]
>>> y = [4,5,6]
>>> x.append(y)
>>> x
[1, 2, 3, [4, 5, 6]]

还是合并?

>>> x = [1,2,3]
>>> y = [4,5,6]
>>> x + y
[1, 2, 3, 4, 5, 6]
>>> x.extend(y)
>>> x
[1, 2, 3, 4, 5, 6] 

Do you mean append?

>>> x = [1,2,3]
>>> y = [4,5,6]
>>> x.append(y)
>>> x
[1, 2, 3, [4, 5, 6]]

Or merge?

>>> x = [1,2,3]
>>> y = [4,5,6]
>>> x + y
[1, 2, 3, 4, 5, 6]
>>> x.extend(y)
>>> x
[1, 2, 3, 4, 5, 6] 

回答 1

问题并没有明确说明您到底想要实现什么。

List具有append方法,该方法将其参数附加到列表:

>>> list_one = [1,2,3]
>>> list_two = [4,5,6]
>>> list_one.append(list_two)
>>> list_one
[1, 2, 3, [4, 5, 6]]

还有extend一种方法,可以将您作为参数传递的列表中的项目追加到后面:

>>> list_one = [1,2,3]
>>> list_two = [4,5,6]
>>> list_one.extend(list_two)
>>> list_one
[1, 2, 3, 4, 5, 6]

当然,有insert一种方法的作用类似于append但允许您指定插入点:

>>> list_one.insert(2, list_two)
>>> list_one
[1, 2, [4, 5, 6], 3, 4, 5, 6]

要在特定的插入点扩展列表,可以使用列表切片(感谢@florisla):

>>> l = [1, 2, 3, 4, 5]
>>> l[2:2] = ['a', 'b', 'c']
>>> l
[1, 2, 'a', 'b', 'c', 3, 4, 5]

列表切片非常灵活,因为它允许用另一个列表中的一系列条目替换列表中的一系列条目:

>>> l = [1, 2, 3, 4, 5]
>>> l[2:4] = ['a', 'b', 'c'][1:3]
>>> l
[1, 2, 'b', 'c', 5]

The question does not make clear what exactly you want to achieve.

List has the append method, which appends its argument to the list:

>>> list_one = [1,2,3]
>>> list_two = [4,5,6]
>>> list_one.append(list_two)
>>> list_one
[1, 2, 3, [4, 5, 6]]

There’s also the extend method, which appends items from the list you pass as an argument:

>>> list_one = [1,2,3]
>>> list_two = [4,5,6]
>>> list_one.extend(list_two)
>>> list_one
[1, 2, 3, 4, 5, 6]

And of course, there’s the insert method which acts similarly to append but allows you to specify the insertion point:

>>> list_one.insert(2, list_two)
>>> list_one
[1, 2, [4, 5, 6], 3, 4, 5, 6]

To extend a list at a specific insertion point you can use list slicing (thanks, @florisla):

>>> l = [1, 2, 3, 4, 5]
>>> l[2:2] = ['a', 'b', 'c']
>>> l
[1, 2, 'a', 'b', 'c', 3, 4, 5]

List slicing is quite flexible as it allows to replace a range of entries in a list with a range of entries from another list:

>>> l = [1, 2, 3, 4, 5]
>>> l[2:4] = ['a', 'b', 'c'][1:3]
>>> l
[1, 2, 'b', 'c', 5]

回答 2

foo = [1, 2, 3]
bar = [4, 5, 6]

foo.append(bar) --> [1, 2, 3, [4, 5, 6]]
foo.extend(bar) --> [1, 2, 3, 4, 5, 6]

http://docs.python.org/tutorial/datastructures.html

foo = [1, 2, 3]
bar = [4, 5, 6]

foo.append(bar) --> [1, 2, 3, [4, 5, 6]]
foo.extend(bar) --> [1, 2, 3, 4, 5, 6]

http://docs.python.org/tutorial/datastructures.html


回答 3

你也可以做…

x += y

You can also just do…

x += y

回答 4

如果要将列表(列表2)中的元素添加到其他列表(列表)的末尾,则可以使用列表扩展方法

list = [1, 2, 3]
list2 = [4, 5, 6]
list.extend(list2)
print list
[1, 2, 3, 4, 5, 6]

或者,如果要串联两个列表,则可以使用+号

list3 = list + list2
print list3
[1, 2, 3, 4, 5, 6]

If you want to add the elements in a list (list2) to the end of other list (list), then you can use the list extend method

list = [1, 2, 3]
list2 = [4, 5, 6]
list.extend(list2)
print list
[1, 2, 3, 4, 5, 6]

Or if you want to concatenate two list then you can use + sign

list3 = list + list2
print list3
[1, 2, 3, 4, 5, 6]

回答 5

如果我们只是这样做x.append(y),则y被引用到x中,这样对y所做的任何更改也会影响附加的x。因此,如果只需要插入元素,则应执行以下操作:

x = [1,2,3] y = [4,5,6] x.append(y[:])

If we just do x.append(y), y gets referenced into x such that any changes made to y will affect appended x as well. So if we need to insert only elements, we should do following:

x = [1,2,3] y = [4,5,6] x.append(y[:])