Questions & answers for senior Python developer interviews in 2022

Python is growing tremendously in popularity due to its simplistic nature and ability to create multiple functionalities with a few lines of code. Today, developers use this programming language to build machine learning, artificial intelligence, Web development, and several other applications. The availability of powerful libraries, ease of understanding, and object-oriented approach make Python a preferred development language. 

Companies offer incredible perks and benefits for senior Python developers who can showcase their skills.

This article will explore the senior Python developer career landscape which will help you to understand the role and requirements

Career prospects: Demand, Job Openings, and Salary 

Senior Python developers can find some of the best-paid jobs. Apart from development jobs, Python developers are in huge demand for roles that involve data analysis, data manipulation, and data visualization. There is much scope for senior Python developers in data analytics and data science. According to Statista, Python is the fourth most widely-used programming language for development. It is becoming increasingly popular for machine learning and artificial intelligence applications.

Some recommended backend developer resources:

In-demand skills for a back-end developer

How to land a high paying back-end developer job

We believe the best indicator of demand for a language is the number of job postings. We analyzed current job postings for senior Python developers on Indeed, Glassdoor, and Naukri.com. Over 70,000 job openings for the role on Naukri.com, followed by 5000+ requirements for seniors Python developers on Indeed, and over 3400 job openings on Glassdoor for the same position. There has been a substantial increase in demand for Python developers in the last couple of years.

Some of the biggest names in the software development industry, such as Google, Dropbox, Netflix, Facebook, and Spotify, use Python for their applications. As a senior Python developer, you have the opportunity to work with one of your dream companies.
According to Payscale.com, the average salary for Python developers in India is INR 5,83,060. This is the median salary, with experienced senior Python developers earning more than INR 1 million a year.

What do companies look for in Python developers during interviews?

From senior Python developers, just as with other developers, companies expect them to have some skills in addition to the technical qualifications. As a senior developer, you should portray a willingness to learn and a passion for the job.

For a senior position, companies will want a solid background in computer science. Your understanding of basic algorithmic concepts such as how to sort, search, and find through various data structures is tested. Most Python developers work on the back-end, so they should understand databases more comprehensively.

Understanding important Python libraries relevant to the role, such as Pandas, Apache Spark, and PyTorch. Companies prefer Python developers who are active on Github and contribute to open-source software projects.

It would help if you tried to tell the interviewers how you stay up to date with the latest developments. You can tell them about your favorite technical books or which blogs interest you.

As a senior Python developer, you should demonstrate impeccable technical skills and come across as a committed and inquisitive candidate to stand out.
We have created an exclusive Python Developer Toolkit to help developers prepare for interviews.

Essential Interview Questions and Answers

What is slicing in Python?

Slicing in Python is used to access parts of sequences like strings, lists, and tuples. The syntax for using slicing is [start:end:step]. We can make the ”step” and just [start:end] to return all the sequence elements.

Here is a subclass of a dictionary:

class DefaultDict(dict):
def missing(self, key):
return []
d = DefaultDict()
d[‘florp’] = 127

Will the following code work? Why or why not?

The code will work because of the standard dictionary object in Python 2 or 3. The use of a subclass dictionary is unnecessary.

However, the subclass won’t work with the code in any case because __missing__ returns a value but does not change the dict itself:

d = DefaultDict()
print d
{}
print d[‘foo’]
[]
print d
{}

As a result, the code will work because it won’t produce any errors. However, it won’t function as it is intended to.

How is memory managed in Python?

There are several methods for memory management in Python:

Python private heap space: All the objects and data structures in Python are in a private heap. Developers do not have access to this private heap. Instead, the Python interpreter takes care of the heap.

Python memory manager: The Python memory manager allocates the heap space for Python objects. The programmer can access some functionalities of the memory manager.

Inbuilt garbage collector: Like Java and C, Python also has an inbuilt garbage collector that recycles all the unused memory to make it available for the heap space.

What will be the output of this code snippet? Explain your answer. 

class Parent(object):
x = 1
class Child1(Parent):
pass
class Child2(Parent):
pass
print Parent.x, Child1.x, Child2.x
Child1.x = 2
print Parent.x, Child1.x, Child2.x
Parent.x = 3
print Parent.x, Child1.x, Child2.x

The output of the code will be:
1 1 1
1 2 1
3 2 3

Most Python developers are confused by the last line of the output. They assume the outcome will be 3 2 1 rather than 3 2 3.

This is because most developers miss that this code changes the value of Parent.x and Child2.x, but not Child1.x. In Python, class variables are internally handled as dictionaries. If a variable name is not in the dictionary of the current class, then the interpreter searches the class hierarchy until the referenced variable name is there.

What is PYTHONPATH?

PYTHONPATH is an environment variable when a module gets imported. It is used to look up the presence of imported modules in various directories.

What are decorators in Python?

Decorators are the functions to add functionality to an existing process without making any changes to the structure of that function. 

In Python, decorators are declared with @decorator_name and called in a bottom-up format.

Here’s an example code snippet:

def decorator_lowercase(function): # defining python decorator
def wrapper():
func = function()
input_lowercase = func.lower()
return input_lowercase
return wrapper
@decorator_lowercase ##calling decoractor
def intro(): #Normal function
return ‘Hello, World!’
hello()
Output: ”hello, world!”

Explain split(), sub(), and subn() methods in Python?

These are the methods that belong to the Python RegEx or ”re” module. They are used to modify strings.

split(): It splits a given string into a list. 

sub(): It is used for finding a substring for a given regex pattern, and then replacing the matched string with a different string.

subn(): A method similar to the sub() method is to return the new string and the number of replacements.

Free Online Assessments for Python Developers 

Here are some resources for Python developers to practice their skills:

Testdome

Mettl Python Programming Assessment

RealPython Quizzes

Takeaway

The prospects of Python developers are promising as big data and machine learning become essential. As Python has applications in machine learning, AI, data science, and analytics, with the right skills and experience, developers can land jobs with the best perks.
Talent500 is the platform where start-ups and Fortune 500 companies build their remote development teams. Join the elite pool of Python developers to get the best career redefining opportunities quickly.