How do I concatenate two lists in Python?

How do I concatenate two lists in Python?

Example:

listone = [1, 2, 3]
listtwo = [4, 5, 6]

Expected outcome:

>>> joinedlist
[1, 2, 3, 4, 5, 6]

Use the + operator to combine the lists:

listone = [1, 2, 3]
listtwo = [4, 5, 6]

joinedlist = listone + listtwo

Output:

>>> joinedlist
[1, 2, 3, 4, 5, 6]

NOTE: This will create a new list with a shallow copy of the items in the first list, followed by a shallow copy of the items in the second list. Use copy.deepcopy() to get deep copies of lists.

Stack Overflow Q#1720421, score: 5635