Intro
List methods are useful, and we have to use these most of the time when working with List. There are more than five methods. But I will write about the five most useful methods that I have used the most.
Python List is equivalent to Array. So, if I use Array word instead of List, you can assume that both are the same.
append()
This is the very first method that uses for adding new value to a list. It takes a value as a parameter and appends the value to the end of the list. Pretty useful, right?
Let’s see an example.
programming_language = ['Python', 'Java', 'C', 'Go']
print(programming_language) # ['Python', 'Java', 'C', 'Go']
programming_language.append('JavaSrcirpt')
print(programming_language) # ['Python', 'Java', 'C', 'Go', 'JavaSrcirpt']extend()
This is another useful method when we need to add a new list with the current list. We are not limited to pass a list, we can also pass strings, tuples, etc. Actually, it takes an iterable as a parameter. And then, the given iterable will add with the end of the current list.
Let’s see some examples.
list1 = ['A', 'B', 'C']
list2 = ['X', 'Y', 'Z']
print(list1) # ['A', 'B', 'C']
list1.extend(list2)
print(list1) # ['A', 'B', 'C', 'X', 'Y', 'Z']
list1.extend('Python')
print(list1) # ['A', 'B', 'C', 'X', 'Y', 'Z', 'P', 'y', 't', 'h', 'o', 'n']insert()
Generally, the append method added a value to the end of a list. But using the insert method, we can add at any position of a list.
It takes two parameters, the first one is for which position we want to put the value, and the second one is for the value. Let’s see some examples.
programming_language = ['Python', 'JavaScript'] print(programming_language) # ['Python', 'JavaScript'] programming_language.insert(1, 'PHP') print(programming_language) # ['Python', 'PHP', 'JavaScript'] programming_language.insert(0, 'C') print(programming_language) # ['C', 'Python', 'PHP', 'JavaScript']
We can get the index of a value by passing it in the index() method.
pop()
This method is used to remove an element from a list. We can pass an index as a parameter to remove a specific element.
If we use this without passing any parameter, it will remove the last element from the list, And return it. Let’s see some examples.
programming_language = ['C', 'Python', 'PHP', 'JavaScript', 'C++'] res = programming_language.pop(2) print(res) # PHP print(programming_language) # ['C', 'Python', 'JavaScript', 'C++'] res = programming_language.pop() print(res) # C++ print(programming_language) # ['C', 'Python', 'JavaScript']
There is another similar method called remove() to remove an element from a list. It takes an element as a parameter, not its index. If there is more than one similar element, then this method will remove the very first one. Let’s see some examples.
programming_language = ['C', 'Python', 'Python', 'PHP', 'JavaScript', 'JavaScript', 'C++', 'Python']
programming_language.remove('C++')
print(programming_language) # ['C', 'Python', 'Python', 'PHP', 'JavaScript', 'JavaScript', 'Python']
programming_language.remove('Python')
print(programming_language) # ['C', 'Python', 'PHP', 'JavaScript', 'JavaScript', 'Python']clear()
The clear method is pretty simple. It removes all the elements from a list and makes it clear. Pretty self-explanatory. Let’s see the following code.
programming_language = ['C', 'PHP', 'JavaScript', 'C++', 'Python', 'Java', 'Go'] print(programming_language) # ['C', 'PHP', 'JavaScript', 'C++', 'Python', 'Java', 'Go'] programming_language.clear() print(programming_language) # []
Conclusion
Using some of these methods, we can build stack and queue data structures easily. We don’t need to write any extra code except these codes.
I hope you got a good idea about these methods. In addition to these, some other methods are not covered in this blog. The two most notable of these are, reverse() and sort(). I will write about these two methods in a separate blog.