Top 30 Python Interview Questions with Answers 2021

Last updated on by Digamber

Python is the most infamous programming language out there. What makes Python so outstanding is its extent of use.

Python is powering various web technologies today, like websites, Softwares, web applications, and is being used in the field of AI, machine learning, and data science extensively. This is why everyone seeks to get a python certification.

A career in the domain of Python programming is rewarding. Python experts are valued more than ordinary programmers. There are ample job opportunities available for python programmers, and its scope in the future is going to augment.

Are you thinking of appearing in a python interview? If yes, then kudos for your decision, but you must go well prepared in any programming interview. You would need to do a little hard work before you face the interviewer.

Well, we have made things easier for you. Here are the top 30 python interview questions and answers in 2021 you should read before appearing in the interview.

So without wasting more time, let’s dive into the main content.

1. List some features of Python?

Python is a programming language and is an interpreted language. An interpreted programming language is not compiled before its execution. Ruby and PHP are two other interpreted programming language.

Python is a language that is favourable for object-oriented programming. In Python, you can develop a definition of classes along with composition and inheritance.

The first-class objects in Python are functions and classes. First-class objects can be assigned to a variable, passed to or returned from other functions.

Python is dynamically typed; thus, unlike c and another statically typed language, you don’t need to declare the type of variable. For example, in c, you need to write int A to declare “A” as an integer and char, and if you want a to be a character, but in Python, you can write a=66 or a=name.

Python is a general-purpose programming language, and that finds its use in a wide range of domains.

Python is a case sensitive programming language.


2. Differentiate list and tuples in Python?

It is possible to edit a list but not a tuple. That list is mutable, and tuple is immutable. A list is slower, whereas tuples are faster. (Tuples are just a type of list in Python).


3. Is Python apt for scripting?

Python is a general-purpose programming language, but it is capable of scripting.


4. Do you know about PEP?

PEP is the abbreviation for the python enhancement proposal. PEP is a collection of general norms that illustrates the formatting of python code for best readability.


5. What is Python’s private heap space?

Python private heap space is the memory management unit in Python. All the memory like data and objects in Python are located in a private heap which is managed by the interpreter.

We don’t have access to this private heap. Python’s memory manager allocates heap space to objects and data.

The garbage collector in Python recycles unused memory and makes it available for use to heap space.


6. What is namespace in Python?

The naming system utilized in Python is Namespace. A naming system ensures unique naming to avoid confrontations.


7. Define functions in Python?

A python function executes when it is called, it is defined by using the def keyword.


8. How would you define python modules?

All the files containing python code are python modules. The modules have an extension as .py. The code inside the modules is executable and can either be function, classes, or variables.


9. Give some examples of built-in modules in Python?

We use several built-in modules in Python. Some of the integrated modules in Python are-

  • JSON
  • Math
  • Random
  • Os
  • SYS


10. Explain PYTHONPATH.

PUTHONPATH is an environment variable. It is used when a module is imported. It is beneficial in checking imported modules in various directories when we import a module. Moreover, the interpreter utilizes it to decide which module to load.


11. What do you know about global variables in Python?

A global function, as the names suggest, is common. Any function can make use of a global variable. A global variable is declared or written outside a function.


12. What are the local variables in Python?

A local variable is specific to a particular function and is declared inside a function or in the local space.


13. What is the importance of indentation in Python?

Indentation is necessary for Python. A code without mandatory indentation would show errors. Indamtion specifies a block of code and loops, classes, functions, etc. are written within it.


14. Differentiate between arrays and lists in Python?

Arrays can store elements of a single data type, but lists are capable of storing elements belonging to different data types.


15. Do you know about the lambda function?

Lambda function can have several parameters but only one statement. It is an anonymous function.


16. Tell something about the __init__ method?

Whenever a new object or instance in a class is created, this method is automatically called to allocate memory.


17. Explain self in Python?

It is another object or instance of a class in Python. Self is the first explicitly included parameter in Python.


18. How does break work in Python?

The break is used to terminate a loop when a condition is satisfied, and controls move to the next statement.


19. How does “continue” work in Python?

Continue permits transferring control to the beginning of the loop when some particular condition is met, skipping some part of the loop in the process.


20. How does pass work in Python?

Pass is useful when programmers want any block of code syntactically but skipping its execution.


21. What is the use of [::-1}?

[::-1} helps reverse the order of a sequence or an array and reprint the copy of the reverse order of these data structures. The original array or sequence, of course, is not affected.


22. What is the use of shuffle?

Shuffle can randomize the placement of elements in a list in Python.


23. How to write comments in Python?

We can add comments in Python after the “#.” An example is below-

#This is a comment in Python.

Docstrings also help in writing comments in Python.


24. Differentiate between range and xrange.

Range returns a python list object whereas, xrange returns an xramge object. Most of the time, they both accomplish the same tasks that are to generate a usable list of integers.

Range generates a static list at runtime, but the xrange does not. The yielding technique is used by range to make values as you need them.
Xrange is useful in generating lists of considerable size and for memory conservation purposes.


25. What is the way to generate random numbers in Python?

To generate a random number, we can utilize the random module. There are a variety of random generators we could use to create random numbers like-

  • random.random()
  • randrange(a, b)
  • uniform(a, b)
  • normalvariate(mean, sdev)


26. Explain pickling.

Pickle is a module in Python capable of accepting any python object, converting it into a string representation, and dumping it into a file by dump function. This whole process is called pickling.


27. What is unpickling in Python?

Unpickling is the opposite process of pickling. It helps in retrieving original objects from the string representation.


28. Why is the use of capitalize() method?

Capitalize () method is to capitalize on the first letter of a string. The original string us returned if it already has its first letter in upper case.


29. Discuss the use of is, not, and in operators?

Operators are function that takes values and produces respective results.

  • is: this operator is used to return true when two operands are right.
  • not: this operator return inverse of a boolean value.
  • in: this checks if some element is present in a sequence.


30. Is it possible to convert one data type into another in Python? If yes, then how to accomplish the same?

The conversion of one data type to another is possible and is done using type conversion.

  • float() – it would convert any data type into a float data type.
  • int() – it would convert any data type into the integer type.
  • ord() – it would turn any character data type into an integer data type.
  • str() – it would convert integer data type into a string data type.
  • hex() – it would convert an integer into a hexadecimal data type.
  • oct() – it would turn an integer into an octal data type.

Similarly, various other methods can change one data type to another.


The verdict

These were some of the critical questions that would help you in any Python interview. I hope you did read these questions and answers. Thanks for reading, and I hope it helps.