Collections.UserList in Python
Python Lists are array-like data structure but unlike it can be homogeneous. A single list may contain DataTypes like Integers, Strings, as well as Objects. List in Python are ordered and have a definite count. The elements in a list are indexed according to a definite sequence and the indexing of a list is done with 0 being the first index.
Note: For more information, refer to Python List
Python supports a List like a container called UserList present in the collections module. This class acts as a wrapper class around the List objects. This class is useful when one wants to create a list of their own with some modified functionality or with some new functionality. It can be considered as a way of adding new behaviors for the list. This class takes a list instance as an argument and simulates a list that is kept in a regular list. The list is accessible by the data attribute of the this class.
[1, 2, 3, 4] 
Original List After Insertion [1, 2, 3, 4, 5]
Traceback (most recent call last): File "/home/9399c9e865a7493dce58e88571472d23.py", line 33, in L.remove() File "/home/9399c9e865a7493dce58e88571472d23.py", line 15, in remove raise RuntimeError("Deletion not allowed") RuntimeError: Deletion not allowed