替换列表中的元素，Python

Question

How a value in a list can be replaced?

Suppose I have the following list :

mylist=[1,3,5,7,4]

and I just want to change the value at index 3 ( which would be 7) with, let's say, 9. (the change is not conditioned )

For earlier versions of python the replace function would work, but how do I do it in Python 3.6?

Answer 1

Console:

➜ ~ python3
Python 3.6.2 (default, Aug 03 2017, 16:34:42) [GCC] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> mylist=[1,3,5,7,4]
>>> mylist[3]=9
>>> mylist
[1, 3, 5, 9, 4]
>>>

Just like that.

Answer 2

>>> mylist = [1,3,5,7,4]

1 . The simplest, go to the list index and assign it the new value.

>>> mylist[3] = 9
>>> mylist
=> [1, 3, 5, 9, 4]

2 . Slicing

>>> mylist = mylist[:3] + [9] + mylist[4:]
>>> mylist
=> [1, 3, 5, 9, 4]