Aizaz Khan

Oct 6, 20212 min

Python List

A list is a container which holds comma-separated values (items or elements) between square brackets where items or elements need not all have the same type.

In general, we can define a list as an object that contains multiple data items (elements). The contents of a list can be changed during program execution. The size of a list can also change during execution, as elements are added or removed from it.

Examples of lists:

  • numbers = [10, 20, 30, 40, 50]

  • names = ["Sara", "David", "Warner", "Sandy"]

  • student_info = ["Sara", 1, "Chemistry"]

Create a Python list

Following list contains all string:

Following list contains a string, an integer and a float values:

use + operator to create a new list that is a concatenation of two lists and use * operator to repeat a list. See the following statements.

List indices:

List indices work the same way as string indices, list indices start at 0. If an index has a positive value it counts from the beginning and similarly it counts backward if the index has a negative value. As positive integers are used to index from the left end and negative integers are used to index from the right end, so every item of a list gives two alternatives indices. Let create a list called color_list with four items.
 
color_list=["RED", "Blue", "Green", "Black"]

ItemREDBlueGreenBlackIndex (from left) 0 1 2 3Index (from right)-4-3-2-1

If you give any index value which is out of range then interpreter creates an error message. See the following statements.

Add an item to the end of the list:

Insert an item at a given position:

Modify an element by using the index of the element:

Remove an item from the list:

Remove all items from the list:

Remove the item at the given position in the list, return it

Slicing list:

This refers to the items of a list starting at index startIndex and stopping just before index endIndex. The default values for list are 0 (startIndex) and the end (endIndex) of the list. If you omit both indices, the slice makes a copy of the original list.

Sort the items of the list in place:

    0