Python programming language has become popular with desktop application development. It has become a must skill set on most of the companies’ requirements in a developer. Python programming language has become popular with machine learning community and is a basic need skill for data scientist/machine-learning developer/deep-learning developer. This article helps you through most of the upto date possible Python interview questions; and covers basic, intermediate and advanced Python interview questions. Example programs and references are provided whenever possible.

Python Interview Questions – Entry Level

Q1 - What kind of language is Python ?

Python is :

  • Interpreted (most of its implementations execute instructions directly, without previously compiling a program into machine level instructions)
  • High-level programming language (provides strong abstraction from internal details of computer; and is human readable)
  • General-purpose programming language (the language could be used to write wide variety of applications)

Q2 - Why is Python called scripting language ?

Python supports scripts: programs written for a Python run-time environment that automate the execution of tasks. These tasks could alternatively be executed one-by-one by a user.

Q3 - What are the benefits of Python ?

There are many benefits in using Python language. Some of them are :

  • Syntax of Python is easy to learn.
  • Python is a high-level programming language. So, it provides a good human readability.
  • Python is cross-platform. Scripts written on an operating system could be run on another with ease.
  • Python has an active community. Many resources and help is available online.
  • Python is extensible. Large variety of third-party modules are available.
  • Python is free. Python programming language can be used for projects without any cost.

Q4 - Give a simple example for Python script.

A simple example where a variable is initialized and printed to the console.

i = 10
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Q5 - How to execute a Python Script ?

If python is installed on the machine, command prompt or shell could be used for executing python scripts with python command.


Q6 - What is Python Shell ?

Python Shell is an interactive command line interface. Python statements can be executed using Python Shell.

Q7 - How do you start Python shell ?

python command will start python shell.

$ python
Python 3.5.2 (v3.5.2:4def2a2901a5, Jun 25 2016, 22:18:55) [MSC v.1900 64 bit (AMD64)] on win32
Type "help", "copyright", "credits" or "license" for more information.

Q8 - What is the command to get Python Version ?

Python Version is displayed when Python Shell is started. Otherwise, without starting Python Shell,python –version  command can be used.

$ python --version
Python 3.5.2

Q9 - Which coding convention is preferred for Python ?

PEP-8[] is the style guide recommended by Python Organization.

Q10 - What are the datatypes available in Python ?

Following are the in-built datatypes in Python programming :

  • Boolean
  • Numeric
    • int
    • float
    • long
    • complex
  • Sequence
    • String
    • List
    • Tuple
  • Set
  • Mapping
    • Dictionary

Q11 - Which conditional statements are available in Python ?

Conditional statements are the programming statements which alter the course of execution based on a condition.

Like other functional programming languages, Python has following conditional statements.

Conditional Statements are also called Control Statements.

Q12 - Which looping statements are available in Python ?

Looping statements are those which repeat the execution of a set of statements in a cyclic manner based on a condition.

Q13 - What is the syntax for Python If statement ?

Python If statement contains if keyword, condition followed by colon symbol (:), and then the statements of if block with indentation.

if condition:
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Condition should evaluate to a boolean value (true or false).

Q14 - What is the syntax for Python For loop ?

for variable in sequence:
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  • for is keyword
  • sequence can be a list, string, typle or rance
  • for ith iteration, the ith element of sequence is loaded to variable
  • statements has to written with indentation

Q15 - Give an example of Python Tuple ?

Tuples are used to store values of different datatypes.

tuple1 = ('Sarath', 'Varma', 1997, 'Kochi')
tuple2 = (1, 2, 3, 4, 5 )
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Elements are separated by comma and are enclosed in parenthesis.

Q16 - How do you access elements of Tuple ?

Like in an Array, elements of Tuple can be accessed using index. Index of first element is 0, and index of last element in the tuple is (length of tuple – 1).

Q17 - How are comments written in Python code ?

Single Line Comments start with # followed by comment content.

Multiple Line Comments are enclosed between triple single quotes or triple double quotes.

# single line commenet


   Multiple line
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Comments improve the readability of a program.

Q18 - Give an example of Python Class.

Following is an example of Python Class.

class Student:
   'Common base class for all students'

   def __init__(self, name, rollNumber): = name
      self.rollNumber = rollNumber
   def displayStudent(self):
      print "Name : ",,  ", Roll Number: ", self.rollNumber
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The Student class contains a constructor for setting the initial state and a method to display student information.

Q19 - Python 2.x or 3.x. Which one would you choose and why ?

Python 2.x is legacy, Python 3.x is the present and future of the language.

Q20 - How do you declare a variable in Python ?

How do you convert float, int, complex value, tuple, list or dictionary to a string ? str() function can be used to convert other data type value to string. str() accepts float, int, complex value, tuple, list or dictionary as an argument and returns string value.

Q21 - What are the mutable builtin datatypes available ?

Mutable datatype are those

  • List
  • Sets
  • Dictionaries

Q22 - What are the immutable builtin datatypes available ?

Immutable datatypes are those

  • Strings
  • Tuples
  • Numbers

Q23 - How to find substring of a string ?

str[start_index:end_index] returns substring of a string, where

  • str is the main string
  • start_index is position of substring from which it starts in main string. If not provided, default value is 0.
  • end_index is the ending index of substring in the main string. If not provided, default value is length of the main string.

Q24 - How to you initialize an array ?

To initialize an array in Python use assignment operator (=) with values separated by comma and enclosed between square brackets.

arr1 = [10, 20, 30, 40, 50]
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Elements of the array can be accessed using index.

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Q25 - Give an example to iterate through all the elements in an array.

For loop can be used to iterate through each element of array.

arr1 = [10, 20, 30, 40, 50]

for i in arr1:
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Q26 - How to find size of a Python Array ?

len() function can be used to find size of Python array, given the dimension.

arr1 = [{10, 20, 30, 40, 50},{10, 20, 30, 40, 50}]

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Q27 - What is Frozen Set in Python ?

Frozen set is an immutable version of a Python Set object.