Python - List Methods
List is one of the fundamental data structures in Python, It provides a flexible way to store and manage a collection of items. It has several built-in methods that allow you to add, update, and delete items efficiently.
Lists in Python can contain items of different data types, including other lists, making them highly flexible to different scenarios. The list object includes several built-in methods that allow you to add, update, and delete items efficiently, as well as to perform various operations on the list’s elements.
Python List Methods
The list methods enable you to manipulate lists easily and effectively, whether you are appending new items, removing existing ones, or even sorting and reversing the list. By using these built-in methods, you can work with lists in Python more effectively, allowing you to write more efficient and readable code.
Printing All the List Methods
To view all the available methods for lists, you can use the Python dir() function, which returns all the properties and functions related to an object. Additionally, you can use the Python help() function to get more detailed information about each method. For example:
print(dir([]))
print(help([].append))
The above code snippet provides a complete list of properties and functions related to the list class. It also demonstrates how to access detailed documentation for a specific method in your Python environment. Here is the output −
['__add__', '__class__', '__class_getitem__', '__contains__', '__delattr__', '__delitem__', '__dir__', '__doc__', '__eq__', '__format__', '__ge__', '__getattribute__', '__getitem__', '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__init_subclass__', '__iter__', '__le__', '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__reversed__', '__rmul__', '__setattr__', '__setitem__', '__sizeof__', '__str__', '__subclasshook__', 'append', 'clear', 'copy', 'count', 'extend', 'index', 'insert', 'pop', 'remove', 'reverse', 'sort']
Help on built-in function append:
append(object, /) method of builtins.list instance
Append object to the end of the list.
(END)
Below, the built-in methods for lists in Python, which are categorized based on their functionality. Let’s explore and understand the basic fuctionality of each method.
Methods to Add Elements to a List
The following are the methods specifically designed for adding new item/items into a list −
| Sr.No. | Methods with Description |
|---|---|
| 1 | **list.append(obj)**Appends object obj to list. |
| 2 | **list.extend(seq)**Appends the contents of seq to list |
| 3 | **list.insert(index, obj)**Inserts object obj into list at offset index |
Methods to Remove Elements from a List
The following are the methods specifically designed for removing items from a list −
| Sr.No. | Methods with Description |
|---|---|
| 1 | **list.clear()**Clears all the contents of the list. |
| 2 | **[list.pop(obj=list-1])**Removes and returns the last object or the object at the specified index from the list. |
| 3 | **list.remove(obj)**Removes the first occurrence of object obj from the list. |
Methods to Access Elements in a List
These are the methods used for finding or counting items in a list −
| Sr.No. | Methods with Description |
|---|---|
| 1 | **list.index(obj)**Returns the lowest index in list that obj appears |
| 2 | **list.count(obj)**Returns count of how many times obj occurs in the list. |
Copying and Ordering Methods
These are the methods used for creating copies and arranging items in a list −
| Sr.No. | Methods with Description |
|---|---|
| 1 | **list.copy()**Returns a copy of the list object. |
| 2 | **[list.sort(func])**Sorts the objects in the list in place, using a comparison function if provided. |
| 3 | **list.reverse()**Reverses the order of objects in the list in place. |