How to remove an element from all lists in a list of lists?

Question

Suppose I have a list of lists.

L = [[1,2,3], ['a',2,True],[1,44,33,12.1,90,2]]

I want to be able to remove all instances of a specific element from each of the sublists in the list L.

So for instance I might want to remove the number 2 so this would produce

L = [[1,3], ['a',True],[1,44,33,12.1,90]]

I tried to use this function + code:

def remove_values_from_list(the_list, val):
    return [value for value in the_list if value != val]

for i in L:
    i = remove_values_from_list(i, '2')

However the output still gives L in its original form and doesn't remove the 2.

Answer 1

i是未连接到的变量L。从中分配了一个值L，然后将其重新分配给其他值；这一点都不会影响L。

一种非破坏性的方法（例如，保存L，为结果创建一个新列表）：

newL = [[value for value in the_list if value != val] for the_list in L]

破坏性的方式（即改变L自身）：

for the_list in L:
    while value in the_list:
        the_list.remove(value)