50 Most Frequently Asked Python Interview Questions and Answers

Python, is one of the most popular programming languages for both beginners and professional developers. It is easy to learn and can be used in various fields. It ranks among today's popular programming languages. 

Learning Python can lead to a lucrative career. You may also encounter technical questions in Python interviews. We know, interviews can be stressful. In that case, preparing for questions you might face beforehand can help you feel more comfortable during the interview.

In this article, we have listed the Python interview questions you may encounter and their answers. However, let’s first take a detailed look at the world of Python. 

 

The 10 Most Popular Python Interview Questions and Answers

 

1. Briefly explain some features of the Python programming language.

Python is a general-purpose, high-level, interpreted language. It has fewer syntactical structures compared to other languages.

 

2. What are the standout features of Python?

The standout features of Python are:

✅ It supports structured programming.

✅ It supports high-level dynamic data types.

✅ It enables dynamic checking of data types.

✅ It allows use in conjunction with Java, COBRA, C, C++, ActiveX, and COM.

 

3. What is Pythonpath?

Pythonpath tells the Python interpreter where to find the module files that can be included in a program. Pythonpath can be set beforehand.

 

4. What are the data types supported in Python?

1. Lists
2. Numbers
3. Strings
4. Dictionaries
5. Tuples

 

5. What are positive and negative indexes?

When searching from left to right, positive indexes apply. When searching from right to left, negative indexes apply. For example, in an array list of size n, the first index for positive indexing is 0. After the first index comes 1, and the last index goes up to n-1.

 

6. What are the disadvantages of Python?

👎 Python has design constraints.

👎 Python is slower compared to C, C++, and Java.

👎 The database access layer is less developed.

 

7. Can we reverse a list in Python?

Yes, it is possible. You can reverse a list in Python by using the reverse() method.

 

8. How do you delete a file in Python?

A file can be deleted in Python with one of the following commands:

1️⃣ os.remove(filename)

2️⃣ os.unlink(filename)

 

9. What is Python mostly used for?

Python uses a scripting language for web applications. The most common area of Python usage is software applications, operating systems, web pages in a browser, and some games. 

 

10. Is Python case sensitive?

Yes, Python is a case-sensitive programming language. 

 

11. How do you comment out multiple lines of code in Python?

In Python, you need to place the # character in front of the comment. To comment out multiple lines, you can hold down the Ctrl key and left click on all lines where you want to place the comment. This way, you can comment out more than one line of code.

 

12. What is the // operator in Python?

In Python, the // operator performs floor division. It rounds the result down to the nearest integer while performing the division. For example:

 

13. What are the arithmetic operators used in Python?

Arithmetic operators in Python are used to perform basic mathematical operations such as addition, subtraction, multiplication, and division. 

Example usage of arithmetic operators;

 

 

14. What are comparison operators in Python?

Comparison operators in Python are used to compare different values. They are used in conditional statements and decision-making processes. 

 

15. What does the != operator mean in Python?

The != operator in Python is used to check if two values are not equal.

 

16. What is += used for in Python?

+= is an assignment operator. In Python, the += operator is used to increase the value of a variable by a certain amount. This operator takes an existing value, adds a specific amount to it, and then assigns the result back to the same variable.

 

17. What is the Python tuple command?

✅ A tuple is used to store multiple items in a single variable.

✅ A tuple is one of the 4 built-in data types in Python used to store data collections. The other data types are List, Set, and Dictionary. 

✅ A tuple is an ordered and unchangeable collection.

✅ They are written in round brackets.

 

18. What is the difference between a list and a tuple in Python?

 

19. What kind of language is Python? Programming or scripting?

Python is a general-purpose programming language. It can be used as a scripting language, while also being a full-fledged programming language that supports a wide range of applications.

 

20. What is Pep 8?

Python offers a coding style known as PEP 8. PEP stands for “Python Enhancement Proposals.” PEP 8 contains various guidelines for writing more readable Python code. Officially written in 2001 by Guido van Rossum, Barry Warsaw, and Nick Coghlan, the main purpose of PEP is to improve code readability and consistency.

 

21. What are Python namespaces?

In Python, namespaces represent the area where the names of variables, functions, classes, and other objects are stored. There are 4 types of namespaces in Python.

1. Built-in namespaces – Contains all the built-in objects in Python and is available when Python starts.
2. Global namespaces – Variables defined at the top level of a Python script or module reside in this namespace. 
3. Enclosing namespaces – These are namespaces shared between nested functions or methods. 
4. Local namespaces – These namespaces are local or internal to a function.

 

22. What are decorators in Python?

Decorators are used to add some design patterns to a function without changing its structure. 

 

23. What are Dict (Dictionary) and List (Set) concepts?

Dict (Dictionary) and list concepts refer to a way of defining dictionaries and lists. 

📍 Example of list syntax;

The code above creates a list as follows.

 

📍 Example of dict syntax;

The code above creates a list as follows.

 

24. What is the difference between .py and .pyc files?

📑 .py files are the Python source files where Python code is written. Before executing the code in .py files, it is compiled into .pyc files.

📑 .pyc files are the result of compiling .py files. A .pyc file is automatically created for a particular Python module when that module is imported.

 

25. What is slicing in Python?

Slicing, also known as slicing, is used to access portions of sequences like lists, tuples, and strings. 

📍 Slicing syntax:

 

26. What are Python modules?

Python modules are files containing Python code. This code can include functions, classes, or variables. 

Some of the commonly used built-in modules are:

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

 

27. What are local variables and global variables in Python?

1️⃣ Global Variables: These are variables defined anywhere in the Python program and are valid throughout the program scope.

2️⃣ Local Variables: These are variables defined within a function and are only valid within the scope of that function.

 

28. What is type conversion in Python?

Type conversion refers to converting one data type into another.

• int() – Converts any data type to an integer type.
• float() – Converts any data type to a float type.
• ord() – Converts characters to integers.
• hex() – Converts integers to a decimal number.
• oct() – Converts an integer to octal format.
• list() –  This function converts any data type to a list type.
• dict() – This function is used to define dictionaries. 
• str() –  Used to convert an integer to a string.

 

29. How is Python installed?

You can install Python on Windows by following these steps:

✔️ Go to the Python website: https://www.python.org/downloads/

✔️ Select the version you want to download.

✔️ Click the Download button and run the downloaded Python installer.

✔️ Install Python on your computer. Use the “cmd python” command in your command prompt to locate where Python is installed on your machine.

✔️ Then you can configure your installation settings. Clicking the "Install Now" button installs with default settings.

✔️ To check that Python was installed correctly, open the Command Prompt and run python --version.

 

30. What is the difference between arrays and lists in Python?

🆚 In Python, arrays and lists have the same data storage method. However, arrays can only hold elements of the same data type, while lists can hold elements of any data type.

The output will be ➡️ array('i', [1, 2, 3, 4]) [1, 'abc', 1.2]

 

31. What are functions in Python?

In Python, functions are a block of code that is only executed when called. “def” keyword is used to define Python functions.

The output of this example ➡️ Welcome to Coderspace.

 

32. How do you call a function in Python?

Python functions are called by using the function name followed by parentheses.

 

33. How many types of functions are there in Python?

There are two types of functions in Python:

1️⃣ Standard library functions - These are built-in functions available in Python.

2️⃣ User-defined functions - These are functions created according to the user’s requirements. 

 

34. What is __init__? What does __init__ do in Python?

__init__ is a method or constructor in Python that is automatically called to allocate memory when a new object/class instance is created. All classes have the __init__ method.

Output:

XYZ

23

20000

 

35. What is the Lambda function in Python?

1. Lambda in Python is a keyword used for defining anonymous functions.
2. A lambda function can have multiple variables depending on what you want to achieve.

 

36. What is self in Python?

Self is an instance or object of a class. This keyword in Python allows you to access the variables, attributes, and methods of a defined class.

 

37. What are break, continue, and pass in Python?

🛑 Break - Allows a loop to be terminated when certain conditions are met, and control is passed to the next statement.

⭕ Continue - Allows skipping part of a loop when a certain condition is met, returning the control back to the start of the loop.

⛔ Pass - Used when a code block is syntactically required but you want to skip its execution. 

 

38. What does [::-1] do?

[::-1] is used to reverse the order of a sequence or array.

Output : array('i', [5, 4, 3, 2, 1])

 

39. How do you comment in Python?

Comments in Python start with the # character. Sometimes, comments are made using doc strings (strings enclosed in triple quotes).

 

39. How do you make the first letter of a string uppercase?

In Python, you can capitalize the first letter of a string using the capitalize() method.

 

40. How do you convert a string to all lowercase in Python?

To convert a string into lowercase, you can use the lower() function.

The output will be “abcd”.

 

41. What is the usage of help() and dir() in Python?

Both help() and dir() can be accessed from the Python interpreter and are used to display a combined documentation of built-in functions. 

1. Help() function: The help() function is used to display the document string.
2. Dir() function: The dir() function is used to display the defined symbols. It makes it easy to learn about an object's attributes. 

 

41. What does len() do?

✅ The len() function is the abbreviation of “length.” 

✅ It returns the length, i.e., the number of characters in a string. 

✅ It is used to determine the length of a string or a list.

The output will be 4.

 

42. How can files be deleted in Python?

To delete a file in Python, you need to import the OS module. Use the os.remove() function.

 

43. How do you add values/elements to a Python array?

Elements can be added to a Python array using the append(), extend() and insert (i,x) functions.

📍 Example syntax:

 

44. How do you remove values/elements from a Python array?

✅ Array elements can be removed using the pop() or remove() functions.

✅ The pop() function returns the deleted value.

✅ The remove() function does not return the deleted value.

 

45. What is the Python split method and how is it used?

The split() method in Python is used to split a specific string.

 

46. How are modules imported in Python?

Modules are imported using the “import” keyword. There are three ways to import modules in Python.

 

47. How are classes created in Python? 

In Python, a class is created using the “class” keyword.

 

49. What is monkey patching in Python?

In Python, monkey patching means modifying a piece of code or class, or any module at runtime. In simpler terms, with monkey patching, we can change the behavior or operation of a class/module at runtime without changing all of the Python code. 

 

50. How do you create an empty class in Python? 

In Python, an empty class is one with no code defined in its block. It is created using the “pass” keyword. 

 

Why Is Python So Popular?

According to the TIOBE index, which measures the popularity of programming languages, Python is the third most popular programming language in the world after Java and C. Four factors can be attributed to this popularity:

1. Ease of use: Python can be a perfect first step for those new to coding and programming. It is relatively easy to learn, making it a great start for getting into programming.
2. Simple syntax: Because of its syntax, which is closer to everyday English, Python code is easier to read and understand than other languages. Its easy-to-read coding style means you can decipher what each line of code does.
3. Growing Community: Because it is an open-source language, anyone can use Python for coding. Moreover, there is a huge community that supports and improves the ecosystem by adding their own contributions and libraries!
4. Versatility: We’ll examine this in more detail, but Python has many areas of usage. Whether you’re interested in data visualization, artificial intelligence, or web development, you can find a use that suits you.

 

Why Learn Python?

We know why Python is so popular, but why should you learn to use Python? In addition to the ease of use and versatility mentioned above, there are many reasons to learn Python:

• Python Developers Are in Demand: There is a demand for people with Python skills across many fields. If you want to start or change your career in this area, it can be a vital skill to have.
• A Good Career: Recent statistics show that the average annual salary for those with Python skills is around £65,000 in the UK.
• Increasing Job Opportunities: Given that Python can be used in many emerging technologies such as artificial intelligence, machine learning, and data analytics, it is likely to be a future-proof skill. Learning Python now can benefit your career for years to come.

 

Conclusion: Learn Python

The Python programming language is one of the simplest and most popular languages you can learn today. No matter your industry, you can find a Python use case in the digital realm. Even if you can’t find any area to apply it, simply mastering a programming language will elevate your analytical thinking skills and make you better than you were before. 

Just like learning a new language or instrument, learning a programming language will help you view problems from different perspectives and improve the way you think. 

There are many resources to learn Python. You can explore online Python trainings or books and watch Python training videos to reach a certain level.

Learning Python is always an advantage for your career. By checking out our Python Bootcamps, you can start your Python journey.