Python list is ordered data type i.e. with heterogeneous data. List are enclosed in brackets  with items comma separated. The list is the most widely used data type in Python.
- 1 How to create a list in Python?
- 2 How to access elements in a list in Python?
- 3 How to change or add elements to a list in Python?
- 4 How to delete or remove elements from a list in Python?
- 5 How to iterate over a List in Python?
- 6 What are Python List Operations?
- 7 What are Python List Built-in functions?
- 8 What are Python List built-in methods?
How to create a list in Python?
List in Python is created using big brackets  with the items in the list be separated by a comma (,). A list can have any number of items and can be of different data types. To have an idea of python data types, please refer to this tutorial:- Python Datatypes.
Let’s explore some of the examples of the list in the following example:-
emptyList =  colors = ['red', 'green', 'blue'] numbers = [1, 2, 3, 4, 5, 6] mixed = ['John', 103, 10.2] matrix = [[1, 2, 3], [4, 5, 6]] print(emptyList) print(colors) print(numbers) print(mixed) print(matrix)
The output of the above program is:-
[‘red’, ‘green’, ‘blue’]
[1, 2, 3, 4, 5, 6]
[‘John’, 103, 10.2]
[[1, 2, 3], [4, 5, 6]]
How to access elements in a list in Python?
We can use a slice operator  and [:] to get items in the list. The concatenation operation can be done using plus (+) sign and asterisk(*) serves as the repetition operator. We can use two types of indexing to get items viz. positive indexing and negative indexing. Positive indexing allows to index items from 0 to n where negative index gives access from backward, where -1 is the last item.
Below is an example of list with simple operations:-
list = ['abcd', 786 , 2.23, 'john', 70.2] print(list) # Prints complete list print(list) # Prints first element of the list print(list[1:3]) # Prints elements starting from 2nd till 3rd print(list[2:]) # Prints elements starting from 3rd element print(list[-1]) # Prints last element
[2.23, ‘john’, 70.2]
How to change or add elements to a list in Python?
Since lists are mutable data types, you can add, edit or delete every item in a list. It is the most flexible data type in Python. You can use a particular index or slice operator to select more than one items to update the value of the list in that position.
colors = ['red', 'green', 'blue'] print("Current list", colors) colors = 'black' print("Updated new color", colors)
Updated new color [‘red’, ‘black’, ‘blue’]
To add elements in the list, append() method of the list is used.
colors = ['red', 'green', 'blue'] print("Current list", colors) colors.append('gray') print("Updated new color", colors)
Updated new color [‘red’, ‘green’, ‘blue’, ‘gray’]
How to delete or remove elements from a list in Python?
We can use del function to remove the whole list or index of items in the list.
colors = ['red', 'green', 'blue', 'gray', 'black'] print("Current list", colors) del(colors) #removes the color green print("Updated list", colors) del(colors[1:3]) print("Updated list", colors)
Updated list [‘red’, ‘blue’, ‘gray’, ‘black’]
Updated list [‘red’, ‘black’]
How to iterate over a List in Python?
A list can be iterated using for loop. Let us see the following example:-
colors = ['red', 'green', 'blue', 'gray', 'black'] for color in colors: print(color)
What are Python List Operations?
|+||Concatenation of two lists|
|*||Repetition operator, to repeat list in multiple times|
|in||Membership operator to check if an item exists in a list|
|not in||Membership operator to check if an item does not exist in a list|
What are Python List Built-in functions?
Python provides the following built-in functions which can be used with the lists.
|cmp(list1, list2)||Compares the elements of left and right lists|
|len(list)||Calculate the length of the list|
|max(list)||Returns the maximum element of the list|
|min(list)||Returns the minimum element of the list|
|list(seq)||Converts any sequence to the list|
|sum()||Returns the sum of all elements in the list|
|sorted()||Returns the new sorted list|
|enumerate()||Returns an enumerated object|
|all()||Returns true if all elements in the list are True|
|any()||Returns true if any element in list is True|
What are Python List built-in methods?
Python provides various methods that can help you perform the various operations in a list. Following are some of the built-in list methods:-
|append()||Add an element to the end of the list|
|count()||Returns the count of the number of items passed as an argument|
|extend()||Add all elements of a list to the another list|
|index()||Returns the index of the first matched item|
|insert()||Insert an item at the defined index|
|pop()||Removes and returns an element at the given index|
|copy()||Returns a shallow copy of the list|
|remove()||Removes an item from the list|
|reverse()||Reverse the order of items in the list|
|sort()||Sort items in a list in ascending order|
|clear()||Removes all items from the list|