Learning Data Structures In Python, Types, and Techniques

Edited By Team Careers360 | Updated on Dec 27, 2023 03:46 PM IST | #Python

Data structures in Python form the backbone of computer programming, and Python, a versatile and powerful programming language, provides a rich set of data structures for developers to work with. In this article, we will explore the world of data structures in Python, from understanding the concept of python tree data structures to exploring the types, built-in, and user-defined data structures you need to learn.

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This Story also Contains

What is a Data Structure?
Types of Data Structures in Python
Data Structures You Need To Learn In Python
Conclusion

Learning Data Structures In Python, Types, and Techniques

Efficient and appropriate data structure selection is critical for writing efficient and maintainable code. Developers can optimise their code and solve complex problems with the use of this versatile programming language. But before starting this article, consider learning these Online Python Courses and Certifications.

What is a Data Structure?

Data structures and algorithms in python is a way to organise and store data in a computer's memory. It defines how data is stored, accessed, and manipulated. Data structures help optimise data storage and retrieval, making it easier to perform various operations efficiently. They are fundamental to solving complex programming problems and enhancing the performance of your code.

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Types of Data Structures in Python

Data structures in Python provide the foundation for managing, accessing, and manipulating data, enabling programmers to tackle complex problems with elegance and efficiency. From the fundamental lists and dictionaries to more specialised structures such as stacks, queues, and trees and more.

Python's extensive repertoire of data structures empowers developers to tailor their solutions to the specific requirements of their projects. DSA in Python offers a variety of data structures, each with specific characteristics and use cases. The primary types of data structures in Python include:

Lists: Lists are ordered collections that can hold elements of various data types. They are dynamic and versatile, supporting operations such as indexing, slicing, appending, and more.
Tuples: Tuples are similar to lists but are immutable, making them efficient for storing unchangeable data.
Dictionaries: Dictionaries are key-value pairs, providing fast data retrieval. They are highly efficient for tasks like mapping and database-like lookups.
Sets: Sets are unordered collections of unique elements, perfect for tasks that require unique values and set operations like union and intersection.
Stacks: Stacks follow the Last-In-First-Out (LIFO) principle, where the most recently added item is the first to be removed. They are useful for tracking function calls and parsing expressions.
Queues: Queues adhere to the First-In-First-Out (FIFO) principle and are essential for tasks such as task scheduling and implementing breadth-first search algorithms.
Linked Lists: Linked lists are dynamic data structures that use pointers to connect elements. They are efficient for inserting and deleting elements in the middle of a list.
Hash Tables: Hash tables, often referred to as dictionaries in Python, use hash functions to map keys to values, enabling efficient data retrieval.
Heaps: Heaps are binary tree-based data structures used for implementing priority queues, crucial for tasks such as scheduling and finding the smallest or largest element. Python provides the heapq module, which makes use of a binary min-heap, enabling you to initialise and manipulate heaps for various purposes.
Arrays: Arrays provide efficient storage and manipulation of sequences with a homogeneous data type, especially numeric data.

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Built-in Data Structures in Python

Python offers several built-in data structures, which are ready to use without additional configuration. These built-in data structures in Python include lists, tuples, dictionaries, and sets. Python's standard library also provides modules like collections, heapq, and queue for more specialised data structures.

User-Defined Data Structures

Sometimes, the built-in data structures may not fully meet your requirements. In such cases, Python allows you to define custom data structures using classes and objects. This flexibility enables you to create data structures tailored to your specific needs. User-defined data structures in Python are essential for building complex applications and libraries.

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Data Structures You Need To Learn In Python

Python offers a rich array of data structures that serve as fundamental building blocks for organising and managing data efficiently. These data structures are essential tools for programmers, allowing them to store, access, and manipulate data in various ways. From the versatile lists and dictionaries to specialised structures such as sets, tuples, and queues, Python's extensive collection of data structures empowers developers to choose the most appropriate one for their specific needs, greatly influencing the efficiency and functionality of their code.

As a Python developer, these data structures are crucial for writing efficient and clean code. Whether you are working on web development, data analysis, scientific computing, or any other field, here are some types of data structures in Python you need to learn in Python:

1. Lists: Versatile and Dynamic

Lists are one of the most commonly used data structures in Python. They are ordered collections of items that can be of any data type, making them versatile and flexible. Lists are defined using square brackets and can be modified after creation, allowing for dynamic updates. Some key features of lists include indexing, slicing, and methods such as append, extend, and remove.

2. Tuples: Immutable and Efficient

Tuples are similar to lists but with one significant difference: they are immutable. Once you create a tuple, you cannot change its content. This immutability makes tuples efficient for certain use cases, such as storing coordinates or data that should not be modified. They are defined using parentheses and support features such as unpacking and indexing.

3. Dictionaries: Key-Value Pairs

Dictionaries are Python's key-value data structure. They are defined using curly braces and consist of key-value pairs. Dictionaries are highly efficient for data retrieval, making them suitable for tasks such as database-like lookups and mapping. Key features include adding, updating, and deleting key-value pairs.

4. Sets: Unordered Collections

Sets are unordered collections of unique elements. They are defined using curly braces or the set() constructor. Sets are ideal for tasks that require unique values, such as finding intersections, unions, and differences between two sets. Some important set operations include add, remove, and mathematical set operations such as union and intersection.

5. Stacks: LIFO Data Structures

A stack is a data structure that follows the Last-In-First-Out (LIFO) principle. You can think of it as a collection of items where the most recently added item is the first one to be removed. Stacks are used in various applications, including parsing expressions, tracking function calls, and more. Python's list can be used to implement a stack.

6. Queues: FIFO Data Structures

Queues, on the other hand, adhere to the First-In-First-Out (FIFO) principle. Items are removed in the order they were added. Queues are essential for tasks like task scheduling, managing resources, and implementing breadth-first search algorithms. The queue module in Python offers various queue implementations, such as Queue and PriorityQueue.

Here is an example code :

import queue

# Create a FIFO queue structure

fifo_queue = queue.Queue()

# Now start adding elements to the queue

fifo_queue.put(1)

fifo_queue.put(2)

fifo_queue.put(3)

# Method to remove elements from the queue

first_item = fifo_queue.get()

second_item = fifo_queue.get()

# Check the queue size

queue_size = fifo_queue.qsize()

# Display the results

print("First item:", first_item)

print("Second item:", second_item)

print("Queue size:", queue_size)

7. Linked Lists: Dynamic Data Structures

Linked lists are dynamic data structures where elements are linked together using pointers. They are efficient for inserting and deleting elements in the middle of the list. Although Python does not have a built-in linked list data structure, you can implement one using custom classes and objects.

8. Hash Tables: Efficient Data Retrieval

Hash tables, or dictionaries in Python, are data structures that use a hash function to map keys to values. This allows for constant-time average retrieval of values based on their keys. Understanding hash tables is crucial for efficient data retrieval and storage in Python.

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9. Heaps: Priority Queues

A heap is a binary tree-based data structure where the parent node is either greater (max heap) or smaller (min heap) than its children. Heaps are often used to implement priority queues, which are essential in tasks such as scheduling jobs by priority or finding the smallest or largest element in a collection. Python provides the heapq module for working with heaps.

10. Arrays: Efficient Sequences

While lists are versatile and dynamic, arrays offer efficient storage and manipulation of sequences with a homogeneous data type. The array module in Python provides space-efficient arrays that are especially useful when dealing with a large amount of numeric data.

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Conclusion

Data structures are the foundation of programming and problem-solving. Understanding the concept of data structures, the various types in Python, built-in and user-defined structures, and the data structures you need to learn is essential for becoming a proficient Application developer. By learning these data structures, you will be well-equipped to tackle diverse programming challenges and build robust, efficient applications in Python.

By utilising this understanding of data structures, you enhance your ability to create resilient Python applications capable of conquering a wide range of programming tasks with elegance and precision.

Frequently Asked Questions (FAQs)

1. What are data structures in Python?

These are a way of organising and storing data to perform operations efficiently. It defines the relationships between data elements and the operations that can be performed on them.

2. Differentiate between an array and a linked list?

Arrays are contiguous blocks of memory with a fixed size, while linked lists consist of nodes where each node contains data and a reference (pointer) to the next node. Linked lists can dynamically grow and shrink, whereas arrays have a fixed size.

3. What is the difference between a set and a dictionary in DSA in Python?

A set is an unordered collection of unique elements, while a dictionary is an unordered collection of key-value pairs, where keys are unique.

4. What are the advantages and disadvantages of using an array?

The advantages of using an array include constant-time access to elements (O(1)) using an index and simplicity in implementation. However, arrays have a fixed size, so resizing can be inefficient, and inserting or deleting elements in the middle may require shifting elements, resulting in O(n) time complexity.

5. Explain the concept of hashing and its role in Python tree data structure.

It is the process of converting data (e.g., a key) into a fixed-size value, which is typically an index for data retrieval. Hashing is used in data structures like hash tables to achieve fast data retrieval by minimising search time to O(1) on average.

Here is an example code :

# Hash function

def hash_function(key, table_size):

hash_value = 0

for char in key:

hash_value = (hash_value * 31 + ord(char)) % table_size

return hash_value

# Use of the hash function

table_size = 10

key = "sample_key"

hashed_index = hash_function(key, table_size)

print(f"Key '{key}' is hashed to index: {hashed_index}")