In this blog, we will see about Data structures using Python. Friends, Data structure is a very crucial topic in any programming language. So, it is very important to clear the concept of data structure in Python.
As we know that Python is a high-level and object-oriented language. There are 2 types of data structures in Python programming.
- Built-in Data Structure
- User-Defined Data Structure
This blog is about Built-in Data Structure using Python.
Built-in data structures in Python are those type which are specific to Python programming.
Below are the built-in data structure in Python
- List
- Tuple
- Set
- Dictionary
Python List
List is similar to array with one major difference. The difference between array and list is that a list can have data with different data types. It means a single List in Python can have number, string and boolean as well.
MyList = [1,2,3,'A','Python',True] print(MyList) |
Count an Item from a List in Python
print(MyList.count('A'))Above code will return number of A exist in MyList.
Reverse a List item in Python
MyList.reverse()
Append new item in a Python List
MyList.append('New Item')To Pop / Remove an item from a List in Python
MyList.pop(index number) MyList.pop(1) #It will remove item which is at index 1 in MyList
Python Tuples
Tuples in Python are similar to Python List but the difference is that Python tuples are not mutable. Meaning that, once item inserted in a Tuple, it can not be modified later.
Syntax to define a Tuple in Python –
MyTuple = (item1, item2, item3……)
MyTuple = (1,2,3) print(MyTuple)
As you know now that, Python tuples can not be modified.
So, let’s try to modify an item in Tuple.
MyTuple = (1,2,3) MyTuple[0] = 5
In above code, I am trying to modify the item at index 0 (zero) in Tuple, but it will throw an error if I will run this code, because Python tuples are not mutable.
Error – “TypeError: ‘tuple’ object does not support item assignment”
Python Dictionary
Dictionary is a built-in data structure in Python which mainly stores data in Key, Value pair.
Syntax to define a Dictionary in Python –
MyDictionary = {1:"Item1",2:"Item2"}
print(MyDictionary)Insert new item in Dictionary
Synatx to insert new item in Dictionary
MyDictionary[Key] = Value;
Now, suppose we have below dictionary –
MyDictionary = {1:"Book1",2:"Book2"}Now, we want to add new item with Key = 3 and value = ‘Book3’
So, as per syntax –
MyDictionary[3] = 'Book3'
Pop/Remove an item from Dictionary in Python
Syntax to remove an item from a Dictionary.
MyDictionary.pop(KeyName)
So, to delete Book3 from above Dictionary, we can write below line in Python –
MyDictionary.pop(3)
So, above line of code will remove an item from MyDictionary where KeyName = 3
Python Set
Set in Python is also an built-in data structure type which stores data in an unordered fashion.
With set, we can find whether it is a subset of a particular set, we can apply union intersection between two sets.
Syntax to define Set in Python
MySet = {item1, item2, item3,….}
Add a new item in Set
Syntax to add new item in Set
MySet.add(Item)
Union
Union is a operation that can be applied on two sets, which returns items from both the sets.
Syntax to use Union in Python
MySet1 = {1,3,5,7,9}
MySet2 = {2,4,6,8,10}
print(MySet1.union(MySet2))Output = {1,2,3,4,5,6,7,8,9,10}
Intersection
Intersection is a operation that returns common item from two sets.
Syntax to use Intersection in Python
MySet1 = {1,2,3,4,5,6}
MySet2 = {2,4,6,8,10}
print(MySet1.intersection(MySet2))Output = {2,4,6}
Summary –
There are two types of data structure in Python, Built-in data structure and User defined data structure.
List, Dictionary, Tuple and Set are built-in data structure in Python.
We have built-in methods to perform insert, remove, update, revers on these data structure.
Hope you like this blog on built-in data structure using Python.
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