Python：从嵌套列表中删除单个元素

Question

I'm having trouble figuring out how to remove something from within a nested list.

For example, how would I remove 'x' from the below list?

lst = [['x',6,5,4],[4,5,6]]

I tried del lst[0][0] , but I get the following result:

TypeError: 'str' object doesn't support item deletion.

I also tried a for loop, but got the same error:

for char in lst:
    del char[0]

Answer 1

Your code works fine. Are you sure lst is defined as [['x',6,5,4],[4,5,6]] ? Because if it is, del lst[0][0] effectively deletes 'x' .

Perhaps you have defined lst as ['x',6,5,4] , in which case, you will indeed get the error you are mentioning.

Answer 2

Use the pop(i) function on the nested list. For example:

lst = [['x',6,5,4],[4,5,6]]
lst[0].pop(0)
print lst  #should print [[6, 5, 4], [4, 5, 6]]

Done.

Answer 3

You can also use "pop". Eg,

list = [['x',6,5,4],[4,5,6]]
list[0].pop(0)

will result in

list = [[6,5,4],[4,5,6]]

See this thread for more: How to remove an element from a list by index in Python?