Top 50 Frequently Asked Python Interview Questions

Python is known to be the most challenging computer programming skill in 2020. In the interviews of Python, it is seen that every individual gets questioned in different forms, though the questions are the same. A discussion of Python Interview Questions has been done below to guide the programmers through the problems. There are three different levels of Python interview questions as per the experience of the programmer.

• Python Interview Questions for the freshers
• Python Interview Questions for the intermediate programmers
• Python Interview Questions for expert programmers

So, let’s start without wasting time.

Python Interview Questions for freshers:

For the freshers, there are some basic questions which are frequently asked by the interviewer:-

• What is Python?

Python is an object-oriented programming language that contains automatic memory management, threads, and exceptions.

• What are the key features of Python?
  The features of Python are:-

1. Interpreted
2. Dynamically-typed
3. Simple and concise
4. Has a huge community
5. This is a free and open-source programming language.

• What type of language is Python, scripting, or programming?

Python is known to be a programming language, but scripting works can also be done with Python.

• What is the difference between tuples and lists?

The significant difference between is, lists are mutable, and the tuples are immutable. The syntax of tuples contains the first brackets – (), and the syntax of lists includes the third brackets – [].

Example:

list_data = [ ‘This’, ’is’, ‘an’, ‘example’ , ‘of’, ‘List’ ]

tuple_data = ( ‘This’, ‘is’, ‘an’, ‘example’, ‘of’, ‘tuple’ )

• Is Python case sensitive?

Yes, Python is a case sensitive programming language. If the syntaxes are not being used with the proper cases, then it’s okay but, if not, then it will not recognize the command. Example:

Myname

NameError: name ‘Myname’ is not defined

• What are the negative indices?

A negative index is used to index starting from the last element of the tuple, list, or any supportive index classes.

Example:

https://qphs.fs.quoracdn.net/main-qimg-a380b1bc159589df5e0b9842e5b56b6d 

https://www.quora.com/What-is-negative-index-in-Python

https://www.quora.com/What-is-negative-index-in-Python

• How long can an identifier be in Python?

As per the official documentation of Python, an identifier could be of any length. The PEP 8 says that all lines should be limited to a maximum of 79 characters but, the PEP 20 says, ‘readability counts’. Thus, a long identifier will violate PEP-8 and PEP-20.

• What is the pass statement in Python?

The pass statement is usually required in Python when there are no requirements of codes but a comment is still needed to make the system syntactically correct. This also works like a null statement in which it does not do anything but keeps code accurate in syntax.

Example:

Input:

https://beginnersbook.com/2018/01/python-pass-statement/

Output:

https://beginnersbook.com/2018/01/python-pass-statement/

• Explain the ternary operator in Python?

Unlike C++, we don’t have ?: in Python, but we have this:

[on true] if [expression] else [on false]

If the expression is True, the statement under [on true] is executed. Else, that under [on false] is executed.

Example:

Input:

https://data-flair.training/blogs/top-python-interview-questions-answer/

Output:

https://data-flair.training/blogs/top-python-interview-questions-answer/

Python Interview Questions for the intermediate programmers:

• Explain join() and split() in Python

With join(), we can join characters from other string with specified characters.

split() lets splitting a string with the specified character.

• When can the else part of a try-except be executed?

In an If-Else statement block, the ‘else’ part is executed when the ‘if’ part is false, and in a try-except block, the else statement gets executed only when no exception is raised in the try statement.

• What is the PYTHONPATH variable?

PYTHONPATH variable is typically used to locate the module files that are imported in the program. It must include the Python source library directory and Python source code directory.

• Can the last object from the list be removed?

Yes, it is possible with the following code:

Output:

• What Does the following statement mean?

S = a + ‘[‘ + b + ‘:’ + c + ‘]’

This statement is an interconnected string. If the a, b, c are strings themselves, then the statement is fine but, if they are not strings, then this statement would be considered as a type error.

• How can an integer be converted to a Unicode character?

The chr(x) built-in function is needed to convert an integer to a Unicode character.

• Identify the problem of the following statement.

The request for n raises a NameError. Since the ‘n’ is a variable local to the function and it can not be accessed from elsewhere. Python only evaluates default parameter value once; every invocation shares the default value. This means, if one invocation is modifying this, the other one will get the same.

• Does recursion cause any kind of trouble?

It surely does. Here are the troubles that recursion causes:

• More function calls are needed.
• It consumes time when calling a function
• It can cause memory overflow as each function call stores a state variable program to the stack, which consumes memory.

• Can the whitespaces be removed from the string “aaa bbb ccc ddd eee”?

There are three ways to remove the whitespaces :

1. Using join() function:-

1. Using a list comprehension:-

1. Using replace():-

• What does the enumerate() function do in Python?

enumerate () iterates through a sequence and extracts the index position, and it’s corresponding value too.

For example:

The output will be:

0 Python

1 C++

2 Scala

• How can the following pattern be created in Python?

*

**

***

****

*****

This pattern can be created using two for loops.

For example:

Python Interview questions for expert programmers:

• What are the palindromes, and how can they be implemented in Python?

Palindromes are a sequence of phrases or words that spells the same from both the forward and backward. To implement it to Python, the following codes are needed:

• What is tuple unpacking?

Suppose there is a tuple number = (1,2,3). The values can be unpacked to variables a,b,c. For example:

Step 1:   

Step 2:   

Step 3:

• What is the Dogpile effect, and how can it be avoided?

When the cache gets expired, and a client hits a website with multiple requests, the aftereffect is named as Dogpile effect. To avoid the process, we can use semaphore locks. Then, even if the value expires, the first request will get locked, and it will start generating the new amounts.

• What is the iterator protocol for Python?

The iterator protocol for Python declares that two functions must be used to build an iterator- iter() and next().

For example:  

2                        

4

6

8

10

• How can Python be used to read a random line?

There are multiple choices to make Python read a random line. The best way to make it do so is by borrowing the choice() method from the random module for this.

For example:-  

• Differentiate between split(), sub(), and subn() methods of the re module.

The re module is what we have for processing regular expressions with Python. Let’s talk about the three methods we mentioned-

• split()- This makes use of a regex pattern to split a string into a list
• sub()- This looks for all substrings where the regex pattern matches, and replaces them with a different string
• subn()- Like sub(), this returns the new line and the number of replacements made

• What a closure in Python?

Closure in Python occurs when a nested function program references a value in its enclosing scope. That means, it remembers the value.

For example:

• What is Frozen Set in Python?

First, let’s discuss what sets are. In Python, the game is a collection of items or values which can not be duplicated in the same area.

For example:

{1,2,3}

This means that it can not be indexed

Traceback (most recent call list):

File“<pyshell#197>” line 1, in <module>

Myset[o]

TypeError: ‘set’ object does not support indexing

So, a set is mutable, and a frozen set is immutable, which means the value can not be changed. This can also be used as a key for a dictionary as it is eligible to do so.

frozenset({1,2,3})

There also are some general questions which the interviewer frequently asks:-

• How do you take input in Python?

With Function input() and raw_input().

• What is a function?

When the sequence of statements is being executed, it requires a name. Let’s define a function to take two numbers and return the more significant number.

• What does zip() function do?

It returns an iterator of tuples.

• What is recursion?

When a function calls itself, it is termed as recursion.

• What is List Comprehension?

It is a way to declare a list in one line.

• Write Python code to print only the letter t

i=0

While s[i]!=’t’

Print (s[i], end-’’)

i+=1

• “Python” – print this string five times in a row

For I in range (6)

print(s)

• What is a control flow statement?

Control flow statements let us disturb the normal execution flow of a program and blend it to our will.

• How would you work with numbers other than those in a decimal number system

Binary, octal, and hexadecimal

• Write your best code to swap two numbers

A,b =2,3

a,b=b,a

a,b

• How can someone declare multiple assignments in one statement?

a,b,c=3,4,5 #This assigns 3, 4, and 5 to a, b, and c respectively

• How to break out of an infinite loop?

Traceback (most recent call last):

File “<pyshell#332>”, line 1, in <module>

counterfunc(7)

File “<pyshell#331>”, line 2, in counterfunc

while(n==7):print(n)

KeyboardInterrupt

• How many types of objects does Python support?

Mutable and immutable.

• What is Python good for?

• Desktop Gui
• Scientific and numeric applications
• Database access
• Applications in business
• Network programming
• Games, 3d graphics
• Applications of education
• Web and internet
• Other python applications

• How can a list be converted to a string?

By using join() method.

• What are assignment operators in Python?

Symbols that are needed to correct the syntax are known to be operators.

• Explain the Logical operators in Python.

There are three logical operators – false and true, 7>7 or right and not 2==2

• Explain identity operators in Python?

The operator ‘is’ and ‘is not’ tell us if two values have the same identity

Like, 10 is ‘10’

True is not false

• What are the bitwise operators in Python?

The operators that value upon bit by bits.

• What data types are supported in Python?

The various Data Types supported in Python are:

• int()
• long ()
• float()
• complex()

• What is docstring?

Docstrings or Python documentation strings are used to document a particular and specific segment of code. It is a multi-line string associated with documentation of modules, functions, methods and classes.

• What is slicing?

In the Programming language of Python, Slicing enables the users to access parts of a sequence. These may be strings, tuples, lists or third party objects.

In this article, you find different suggestions of the frequently asked python interview questions which can help from the freshers to the experts. Read the answers thoroughly and understand them properly. Hope you find the above pieces of information helpful.