How to allow list append() method to return the new list How to allow list append() method to return the new list python python

How to allow list append() method to return the new list


python list append

Don't use append but concatenation instead:

yourList = myList + [40]

This returns a new list; myList will not be affected. If you need to have myList affected as well either use .append() anyway, then assign yourList separately from (a copy of) myList.

python list append

In python 3 you may create new list by unpacking old one and adding new element:

a = [1,2,3]b = [*a,4] # b = [1,2,3,4]

when you do:

myList + [40]

You actually have 3 lists.

python list append

list.append is a built-in and therefore cannot be changed. But if you're willing to use something other than append, you could try +:

In [106]: myList = [10,20,30]In [107]: yourList = myList + [40]In [108]: print myList[10, 20, 30]In [109]: print yourList[10, 20, 30, 40]

Of course, the downside to this is that a new list is created which takes a lot more time than append

Hope this helps

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