Top 15 Python Interview Questions With Answers

Top 15 Python Interview Questions

Python will continue to be one of the most widely used and popular programming languages in the business, regardless of how many languages a programmer learns. It’s a popular choice among both new and experienced programmers.

We’ve put together a list of the most often asked Python Interview Questions and Answers to help you prepare for the Python interview questions you might be asked during your interview.

We’ve covered all of the most commonly asked basic and advanced Python programming questions in our list of Python Scripting interview questions, along with extensive solutions to help you breeze through the employment interview.

To assist you in preparing for your upcoming interview, we have covered practically all of the relevant Python interview questions for freshers and experienced applicants.

This comprehensive list of Python interview questions will help you ease your Python programming job interview.

1. What is your understanding of Python?

Python is a scripting language that is extremely comprehensive, interactive, and object-oriented. It was created with the intention of making the text more readable for internet users. Apart from punctuation, it uses a variety of keywords in other languages. Unlike other languages, it contains fewer syntactic structures. Python is used to create AI-based intuitive web and mobile app development.

2. What are the benefits of using Python?

Python is a programming language that features objects, modules, threads, exceptions, and memory management that is automatic. Its advantages are well-known. It is simple and straightforward to use, portable, extensible and has a built-in structure while being open-source. 

3. What is pickling and unpickling?

Pickle takes any Python object and converts it to a string representation, which it then dumps into a file using the dump function. Pickling is the name for this method. Whereas, the process of recovering original Python objects from a stored text representation is known as unpickling.

4. How is Python interpreted?

Python is an interpreted programming language. Python programs are compiled from source code and run directly. It translates the programmer’s source code into an intermediate language, which is then translated into machine language, which must be executed.

5. How is memory managed in Python?

Memory management is handled via Python’s own heap space. All Python objects and data structures are stored in a private heap. This private heap, which is controlled by the Python interpreter, is not accessible to the programmer.

Allocating heap space for Python objects is handled by Python memory management. Programmers can use the core API to access some programming tools.

Python has a built-in garbage collector that recycles all unused memory, freeing it and making it available to the heap.

6. What are Python namespaces?

In Python, a namespace refers to the name that is assigned to each object. Variables and functions are the objects. Each object’s name and space (the address of the outer function in which the item is) are created as it is formed. The namespaces are stored in Python as a dictionary, with the namespace as the key and the object’s address as the value. In Python, there are four different types of namespaces:

  1. Built-in namespace– These namespaces contain all of Python’s built-in objects and are accessible at all times.
  2. Global namespace– These are the namespaces for all of the objects created at the main program level.
  3. Enclosing namespaces– These namespaces belong to the higher or outer function.
  4. Local namespaces– These namespaces are found in the inner or local function.

7. What are decorators in Python?

Decorators are used to change the appearance of a function without changing its structure. Decorators are usually defined prior to the function they will be enhancing. To use a decorator, we must first specify its function. Then we write the function to which it will be applied and simply place the decorator function above the function to which it will be applied. The @ symbol is used before the decorator in this case.

8. What is the difference between a list and a tuple?

The difference between a list and a tuple is that a list can be mutated, whereas a tuple cannot. A Tuple can be hashed as a dictionary key, for example.

9. How are arguments passed by value or by reference?

In Python, everything is an object, and all variables are references to objects. The functions determine the reference values. As a result, you won’t be able to change the value of the references. If the objects are mutable, you can change them.

10. What built-in type does python provide?

Python provides two built-in types: 

1) Mutable and 2) Immutable.

Mutable built-in types are:

  • List
  • Sets
  • Dictionaries
  • Immutable built-in types
  • Strings
  • Tuples
  • Numbers

Immutable built-in types are:

  • Strings
  • Tuples
  • Numbers

11. What is slicing in Python?

Slicing is a technique for gaining access to specific bits of sequences such as lists, tuples, and strings. [start:end:step] is the slicing syntax. This step can also be skipped. When we type [start:end], we get a list of all the elements in the sequence from the beginning (inclusive) to the end-1 element. It means the ith element from the end if the start or end element is negative i. The step represents the jump or the number of components that must be skipped. If there is a list, for example, [1,2,3,4,5,6,7,8]. Then, by printing every second element, [-1:2:2] will return elements from the last to the third element. [8,6,4] is an example.

12. What are python modules? Name some commonly used built-in modules in Python?

Python modules are executable files that contain Python code. Functions, classes, and variables can all be used in this code. A Python module is a .py file that contains code that may be executed.

The following are some of the most often used built-in modules:

  • os
  • sys
  • math
  • random
  • data time
  • JSON

13. Is indentation required in python?

Indentation is required in Python. It designates a coding block. An indented block contains all of the code for loops, classes, functions, and so on. The most common method is to use four space characters. Your code will not execute correctly if it is not indented, and it will also throw errors.

14. What is self in Python?

A class’s instance or object is called Self. This is explicitly supplied as the first parameter in Python. However, in Java, where it is optional, this is not the case. With local variables, it’s easier to distinguish between a class’s methods and attributes.

In the init method, the self variable refers to the newly created object, whereas it relates to the object whose method was called in other methods.

15. What are negative indexes and why are they used?

In Python, the sequences are indexed and include both positive and negative numbers. The positive numbers utilize ‘0’ as the first index and ‘1’ as the second index, and the procedure continues in this manner.

The index for a negative number begins with ‘-1,’ which is the last index in the sequence, and ends with ‘-2,’ which is the penultimate index, and the sequence continues as it does for a positive number.

The negative index is used to remove any new-line spaces from the string, allowing it to accept the S[:-1] character as the final character. The negative index is also used to represent the index in the correct order of the string.

I hope this set of Python Interview Questions will help you in your interview preparation. Best wishes!

 

If you are looking for Python developers for your next project, get in touch with us.

Also, if you have a question for us? Please let us know in the comments box, and we’ll get back to you as soon as possible. 

10 Best Python App Development Frameworks in 2023

python-app-development-frameworks

python-app-development-frameworks

The latest Statista research shows that over 48% of developers worldwide use Python for software development. Python is among the most popular programming languages, with major firms like IBM, NASA, Spotify, and Instagram using them.

The popularity of Python is because of its vast range of libraries, packages, and frameworks. A Python application framework is a collection of modules and packages that allows developers to build apps through a pre-built implementation of redundant functions. They release developers from minor issues like thread management, sockets, and protocols.

There are several Python frameworks for mobile app development and web app development that enable seamless, efficient, and swift application development. We’ve listed the best frameworks in this blog.

Why Should I Go for Python App Development?

Python is best suited for creating dynamic applications integrated with CRUD operations and avoiding repetitive coding for activities like authentication and sessions. It also provides an execution system when you’re building a separate UI with associated logic. 

Python is also the best option when you have strict deadlines and time and resource constraints. From full-stack and DevOps to AI/ML, data engineering, and data science, Python offers all-around development options. 

Here are some reasons why Python is the king of programming languages:

  • Python’s vibrant range of frameworks, libraries, and tools enables swift development and gives access to code templates.
  • Python is a high-level programming language and quite close to English, hence it has a lower learning curve compared to other coding languages.
  • Python has a large developer community and rich documentation with new frameworks and libraries being added quite often.

What are the Types of Python App Development Frameworks?

There are three types of Python application frameworks: Microframework, Full-stack, and Asynchronous Framework.

Micro Framework

Micro Framework

A Python micro-framework is easy to use with basic capabilities or features required for web development and does not have added functionalities like form validation and data abstraction layers. They are lightweight and useful for building small applications.

Some popular examples of Micro Python frameworks include CherryPy, Bottle, Falcon, and Dash.

Full-Stack Framework

Full-Stack Framework

A full-stack framework is an end-to-end solution for web and app development with functionalities like template layouts, form validation, form generator, and so on. It is the most convenient and popular Python framework since it offers features of back-end functions, front-end interfaces, and databases. 

Some popular examples of Full-stack Python frameworks include Django, Pylons, CubicWeb, and Giotto

Asynchronous Framework

Asynchronous Framework

The asynchronous framework empowers developers to work on large amounts of concurrent connections, databases, web servers, connection libraries, high-performance networks, and so on. It is gaining widespread popularity recently since the development of the Asyncio library.

Some examples of Asynchronous Python frameworks are Tornado, Growler, AIOHTTP, and Sanic.

How to Choose the Right Python App Development Framework?

The most essential factor before selecting the right framework for development is the nature, size, and complexity of the project. For example, you can opt for a micro-framework for a smaller project while considering full-stack frameworks for larger projects. 

Also, here are some examples of frameworks based on the project’s nature.

Python application development

Other factors that you can consider before selecting a Python app development framework for your project are

  • Scalability to handle traffic load when they run on several servers
  • Core libraries like authentication, data validation, URL mapping/rewriting, and templating.
  • Comprehensive documentation with tutorials, sample codes, blogs, and snippets.
  • Easy installation of the preferred Python framework.

10 Most Popular Python App Development Frameworks

Here’s a list of the most popular python app development frameworks:

Django

Django is a high-level development Python framework for creating both mobile and web apps that operate on a power ORM and follows the Model View Controller (MVC) pattern, making the code reusable and readable. It has built-in tools like URL routing/parsing, authentication system, form validation, template engine, and caching to ensure a swift development process.

Django follows the DRY (Don’t Repeat Yourself) concept and focuses on rapid app development with a neat design. It is the first choice of developers for any Python project due to its versatility, customization, scalability, deployment speed, simplicity, and compatibility with the latest Python versions.

According to a Stack Overflow survey of 2020, Django and Flask are the most popular Python frameworks. Popular examples of apps built with Django include Instagram and Spotify.

Key Features of Django:

  • Enables execution of automated migrations
  • Robust security
  • Enhanced web server support
  • Comprehensive documentation
  • Vast add-ins with SEO optimization

Flask

flask-framework

Flask is an open-source, lightweight, and the best Python microframework with a built-in development server, debugger, HTTP request processing, file storage, and support for establishing client-side sessions. It has a modular and adaptable design and added compatibility with Google App Engine.

Besides Django, Flask is another popular Python framework with the Werkzeug WSGI toolkit and Jinja2 template. Flask comes under the BSD license and it is inspired by the Sinatra Ruby framework. Popular examples of apps developed with Flask include Lyft and Netflix.

Key Features of Flask:

  • Jinja2 templating and WSGI compliance
  • Unicode-based with secure cookie support
  • HTTP request handling capability
  • RESTful request dispatch handling
  • Built-in server development and integrated unit-testing support
  • Plugs into any ORM framework

Web2Py

Web2Py

Web2Py is an open-source, full-stack, and scalable Python application framework compatible with most operating systems, both mobile-based and web-based. It is a platform-independent framework that simplifies development through an IDE that has a code editor, debugger, and single-click deployment.

Web2Py deals with data efficiently and enables swift development with MVC design but lacks configuration files on the project level. It has a critical feature, a ticketing system that auto-generates tickets in the event of issues and enables tracking of issues and status.

Key Features of Web2py:

  • No configuration and installation needed
  • Enables use of NoSQL and relational databases
  • Follows MVC design with consistent API for streamlining web development
  • Supports internationalization and role-based access control
  • Enable backward compatibility
  • Addresses security vulnerabilities and critical dangers

TurboGears

TurboGears

TurboGears is an open-source, full-stack, data-driven popular Python web app framework based on the ObjectDispatch paradigm. It comes with a powerful ORM and supports intelligible templating.

TurboGears is useful for building both simple and complex apps with its features implemented as function decorators with multi-database support. It offers high scalability and modularity with MochiKit JavaScript library integration and ToscaWidgets for seamless coordination of server deployment and front end.

Key aspects of TurboGears:

  • MVC-style architecture
  • Provides command-line tools 
  • Extensive documentation
  • Validation support with Form Encode
  • It uses pylons as a web server
  • Provides PasteScript templates

Falcon

Falcon

Falcon is a reliable and secure back-end micro Python application framework used for developing highly-performing microservices, APIs, and large-scale application backend. It is extensible and optimized with an effective code base that promotes building cleaner designs with HTTP and REST architecture.

Falcon provides effective and accurate responses for HTTP threats, vulnerabilities, and errors, unlike other Python back-end frameworks. Large firms like RackSpace, OpenStack, and LinkedIn use Falcon.

Falcon has the ability to handle most requests with similar hardware to its contemporaries and has total code coverage.

Key Features of Falcon:

  • Intuitive routing with URL templates
  • Unit testing with WSGI mocks and helpers
  • Native HTTP error responses
  • Optimized and extensible code base
  • Upfront exception handling support
  • DRY request processing
  • Cython support for enhanced speed

CherryPy

Cherrypy

CherryPy is an object-oriented, open-source, Python micro framework for rapid development with a robust configuration system. It doesn’t require an Apache server and enables the use of technologies for Cetera templating and accessing data.

CherryPy is one of the oldest Python development frameworks mainly for web development. Applications designed with CherryPy are self-contained and operate on multi-threaded web servers. It has built-in tools for sessions, coding, and caching.

Popular examples of CherryPy apps include Hulu and Juju.

Key features of CherryPy:

  • Runs on Android
  • Flexible built-in plugin system
  • Support for testing, profiling, and coverage
  • WSGI compliant
  • Runs on multiple HTTP servers simultaneously
  • Powerful configuration system

Tornado

Tornado

Tornado is an open-source asynchronous networking Python framework that provides URL handling, HTML support, database support, and other crucial features of every application.

Tornado is as popular as Django and Flask because of its high-performing tools and features except that it is a threaded framework instead of being WSGI based. It simplifies web server coding, handles thousands of open connections with concurrent users, and strongly emphasizes non-blocking I/O activities for solving C10k difficulties. 

Key features of Tornado:

  • Web templating techniques
  • Extensive localization and translation support
  • Real-time, in-the-moment services
  • Allows third-party authorization, authorization methods, and user authentication
  • Template engine built-in
  • HTTP client that is not blocking

AIOHTTP

AIOHTTP

AIOHTTP is a popular asynchronous client-side Python web development framework based on the Asyncio library. It depends on Python 3.5+ features like Async and Awaits. 

AIOHTTP offers support for client and server WebSockets without the need for Callback Hell and includes request objects and routers for redirecting queries to functions.

Key highlights of AIOHTTP Python framework:

  • Provides pluggable routing
  • Supports HTTP servers
  • Supports both client and WebSockets without the callback hell.
  • Middleware support for web servers
  • Effective view building

Popular Cross-Platform Python Frameworks for Mobile App Development

Here are the two main cross-platform Python mobile app frameworks: Kivy and Beeware

Kivy

Kivy

Kivy is a popular open-source Python framework for mobile app development that offers rapid application development of cross-platform GUI apps. With a graphics engine designed over OpenGL, Kivy can manage GPU-bound workloads when needed.

Kivy comes with a project toolkit that allows developers to port apps to Android and has a similar one for iOS. However, porting Python apps to iOS currently is possible with Python 2.7.

Features of Kivy:

  • Enables custom style in rendering widgets to give a native-like feel
  • Enhanced consistency across different platforms with a swift and straightforward approach
  • Well-documented, comprehensive APIs and offers multi-touch functionalities

BeeWare

BeeWare

BeeWare is another Python framework for mobile app development that enables developers to code apps in Python and cross-compilation for deployment on several mobile platforms and OS like Android, Linux GTK, iOS, and Windows.

The primary repository of BeeWare gets updated often with added commercial support including technical support, consulting, and training.

Features of BeeWare:

  • Enables code reusability
  • Provides consistency across apps with the native look and feel
  • Includes tools like Briefcase and Toga that are designed for precise functions
  • Agile developer community

Still Confused? Partner with OnGraph for Python App Development

Python has several app development frameworks and selecting the perfect fit can prove tough with several factors to note from budget and complexity to scalability, additional features, learning curve, and so on. 

Fortunately, you can get the right pick for your project with OnGraph, a leading Python Development Company that offers tailored Python development solutions with proven expertise in various Python application frameworks like Django, Flask, TurboGears, Kivy, and Tornado.

Reach our Python experts now to develop a successful project.