Top 20 Python Interview Questions You Must Prepare

Python is among the most popular and sought-after languages today. Major organizations in the world build programs and applications using this object-oriented language. Once you’ve had enough understanding of the various concepts of Python, it’s time to give a shot at some interviews. To increase your chances of clearing them, we have prepared the most frequently asked Python Interview Questions and Answers that will help you to prepare for the interview questions on Python that an interviewer might ask you during your interview. In this list of Python interview questions, we have covered all commonly asked Basic Python programming questions to help you clear the job interview easily.

Python Interview Questions and Answers


1. What is Python?

Python is a highly comprehensive, interactive, and object-oriented scriptwriting language. It is specifically developed with the purpose of making the content highly readable among the net surfers. Python makes use of various English keywords other than just punctuations. It also has lesser syntactical constructions like in other languages.


2. What are the distinct features of Python?

The distinct features of Python include the following.

  1. Structured and functional programming are supported.
  2. It can be compiled to byte-code for creating larger applications.
  3. Develops high-level dynamic data types.
  4. Supports checking of dynamic data types.
  5. Applies automated garbage collection.
  6. It could be used effectively along with Java, COBRA, C, C++, ActiveX, and COM.


3. How Python is interpreted?

Python language is an interpreted language. Python program runs directly from the source code. It converts the source code that is written by the programmer into an intermediate language, which is again translated into machine language that has to be executed.


4. How is memory managed in Python?

Memory management in python is managed by Python private heap space. All Python objects and data structures are located in a private heap. The programmer does not have access to this private heap. The python interpreter takes care of this instead. The allocation of heap space for Python objects is done by Python’s memory manager. The core API gives access to some tools for the programmer to code.


5. What is PYTHONPATH?

It is an environment variable which is used when a module is imported. Whenever a module is imported, PYTHONPATH is also looked up to check for the presence of the imported modules in various directories. The interpreter uses it to determine which module to load.


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

Python modules are files containing Python code. This code can either be functions classes or variables. A Python module is a .py file containing executable code.

Some of the commonly used built-in modules are:

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


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


Global Variables:

Variables declared outside a function or in global space are called global variables. These variables can be accessed by any function in the program.

Local Variables:

Any variable declared inside a function is known as a local variable. This variable is present in the local space and not in the global space.


8. How Python is interpreted?

Python language is an interpreted language. Python program runs directly from the source code. It converts the source code that is written by the programmer into an intermediate language, which is again translated into machine language that has to be executed.

9. Explain pickling and unpickling.

pickle is a standard module which serializes & de-serializes a Python object structure. pickle module accepts any Python object converts it into a string representation & dumps it into a file(by using dump() function) which can be used later, the process is called pickling. Whereas unpickling is the process of retrieving the original Python object from the stored string representation for use.

10. What is self in Python?

Self is an instance of an object of a class. In Python, this is explicitly included as the first parameter. However, this is not the case in Java where it’s optional.  It helps to differentiate between the methods and attributes of a class with local variables. The self variable in the init method refers to the newly created object while in other methods, it refers to the object whose method was called.


11. What is namespace in Python?

In Python, every name introduced has a place where it lives and can be hooked for. This is known as a namespace. It is like a box where a variable name is mapped to the object placed. Whenever the variable is searched out, this box will be searched, to get the corresponding object.


12. What are the tools that help to find bugs or perform the static analysis?

PyChecker is a static analysis tool that detects the bugs in Python source code and warns about the style and complexity of the bug. Pylint is another tool that verifies whether the module meets the coding standard.


13. What is a pass in Python?

Pass means, no-operation Python statement, or in other words, it is a place holder in the compound statement, where there should be a blank left and nothing has to be written there.


14. What is a dictionary in Python?

Python dictionary is one of the supported data types in Python. It is an unordered collection of elements. The elements in dictionaries are stored as key-value pairs. Dictionaries are indexed by keys.


15. What is a map function in Python?

The map() function in Python has two parameters, function and iterable. The map() function takes a function as an argument and then applies that function to all the elements of an iterable, passed to it as another argument. It returns an object list of results.


16. What is a Python module?

Modules are independent Python scripts with the .py extension that can be reused in other Python codes or scripts using the import statement. A module can consist of functions, classes, and variables, or some runnable code. Modules not only help in keeping Python codes organized but also in making codes less complex and more efficient.


17. Is indentation optional in Python?

Indentation in Python is compulsory and is part of its syntax. All programming languages have some way of defining the scope and extent of the block of codes; in Python, it is indentation. Indentation provides better readability to the code, which is probably why Python has made it compulsory.


18. Can we make multiline comments in Python?

Python does not have a specific syntax for including multi-line comments like other programming languages. However, programmers can use triple-quoted strings (docstrings) for making multiline comments as to when a docstring is not used as the first statement inside a method, it gets ignored by Python parser.


19. What is self-keyword in Python?

Self-keyword is used as the first parameter of a function inside a class that represents the instance of the class. The object or the instance of the class is automatically passed to the method that it belongs to and is received in the ‘self-keyword.’ Users can use another name for the first parameter of the function that catches the object of the class, but it is recommended to use ‘self-keyword’ as it is more of a Python convention.


20. What is docstring in Python?

Python lets users include a description (or quick notes) for their methods using documentation strings or docstrings. Docstrings are different from regular comments in Python as, rather than being completely ignored by the Python Interpreter like in the case of comments, Python documentation strings can actually be accessed at the run time using the dot operator when docstring is the first statement in a method or function.


So, that sums up the list of Top 20 Python interview questions. Learning never gets easier, you need to get better. As a high-in-demand language used by Data Science candidates, learning Python is always a plus. If you wish to learn Python and gain expertise in quantitative analysis, data mining, and the presentation of data to see beyond the numbers by transforming your career into Data Scientist role, check out our Python Certification Training!

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