200+ Python Software Developer Interview Questions and Answers

The super keyword is used to call the superclass's methods and constructors in a subclass in Python.

• super() is used to call the superclass's methods and constructors in a subclass.

• It helps in achieving method overriding and method resolution order in multiple inheritance.

• super() is commonly used in the __init__() method of a subclass to initialize the superclass's attributes.

Program to check if two words are anagrams without using built-in functions

• Create a function that takes in two strings as input

• Convert both strings to lists of characters

• Sort the lists of characters

• Check if the sorted lists are equal to determine if the words are anagrams

Yes, I have implemented context managers in my applications.

• Implemented context managers using the 'with' statement in Python

• Used contextlib module to create custom context managers

• Managed resources like file handling, database connections, and locks using context managers

Static methods are bound to the class itself, while instance methods are bound to instances of the class. Use @staticmethod decorator for static methods.

• Static methods do not have access to class or instance attributes, while instance methods do.

• Instance methods can modify instance state, while static methods cannot.

• To define a static method in Python, use the @staticmethod decorator before the method definition.

• Example: ```python class MyClass: @staticmethod def static_metho...read more

Use a for loop to check if a number exists in a list and print 'yes' or 'no'.

• Initialize a list of numbers, e.g., numbers = [1, 2, 3, 4, 5].

• Use a for loop to iterate through the list.

• Check if the given number is equal to any element in the list.

• Print 'yes' if found, otherwise print 'no'.

• Example: for num in numbers: if num == target: print('yes') else: print('no')

A Python program using historical stock data and algorithms to determine the best price for selling stocks.

• Use historical stock data to analyze trends and patterns

• Implement algorithms like moving averages or RSI to predict stock price movements

• Consider factors like volume, volatility, and market sentiment

• Optimize the program for real-time data updates and accurate predictions

Inheritance is a mechanism in which a new class inherits attributes and methods from an existing class.

• Inheritance allows a class to reuse code from another class.

• Python supports single, multiple, and multilevel inheritance.

• Example: class ChildClass(ParentClass):

To swap two numbers without using a swap function or a third variable, use arithmetic operations.

• Add the two numbers together and store the result in one of the variables

• Subtract the second number from the sum and store the result in the second variable

• Subtract the original first number from the sum and store the result in the first variable

The request-response cycle is the process of communication between a client and server in web applications.

• 1. Client sends a request to the server via HTTP/HTTPS protocols.

• 2. The server processes the request, often involving database queries.

• 3. The server generates a response, typically in HTML, JSON, or XML format.

• 4. The response is sent back to the client, which renders the content for the user.

• 5. Technologies involved include web servers (e.g., Apache, Nginx), application ...read more

Learn to create a GitHub repository and push VS Code project files using Git commands.

• 1. Create a GitHub account if you don't have one.

• 2. Go to GitHub and click on 'New' to create a new repository.

• 3. Fill in the repository name, description, and choose visibility (public/private).

• 4. Initialize the repository with a README if desired, then click 'Create repository'.

• 5. Open your project in VS Code and open the terminal.

• 6. Initialize Git in your project folder using: `git init`....read more

Convert XML to JSON in Python using libraries like xmltodict and json.

• Use the xmltodict library to parse XML: `import xmltodict`.

• Read the XML file: `with open('file.xml') as xml_file:`.

• Convert XML to a Python dictionary: `data_dict = xmltodict.parse(xml_file.read())`.

• Use the json library to convert the dictionary to JSON: `import json` and `json_data = json.dumps(data_dict)`.

• Write the JSON data to a file: `with open('file.json', 'w') as json_file: json_file.write(json_data)`.

Decorators are functions that modify other functions, while GIL is a mutex that protects access to Python objects.

• Decorators allow you to wrap a function to extend its behavior without modifying its code.

• Example of a simple decorator: def my_decorator(func): def wrapper(): print('Something is happening before the function is called.') func() print('Something is happening after the function is called.') return wrapper @my_decorator def say_hello(): print('Hello!')

• The Global In...read more

A medium-level binary search problem involves searching for an element in a sorted array efficiently using the binary search algorithm.

• Binary search operates on sorted arrays or lists, reducing search space by half each iteration.

• Example: Finding the index of a target value in a sorted array, e.g., searching for 7 in [1, 3, 5, 7, 9].

• Time complexity is O(log n), making it much faster than linear search (O(n)) for large datasets.

• It can be adapted for finding the first or last o...read more

API calls are authenticated using tokens or API keys.

• Use tokens or API keys to authenticate API calls

• Implement OAuth for secure authentication

• Set up API rate limiting to prevent abuse

• Use HTTPS to encrypt data during transmission

Threading allows multiple tasks to run concurrently. Generator functions produce a sequence of values. Decorators modify functions or methods.

• Threading in Python allows for concurrent execution of tasks.

• Generator functions use the yield keyword to produce a sequence of values.

• Decorators in Python are used to modify the behavior of functions or methods.

• Example: Threading - threading.Thread(target=my_function).start()

• Example: Generator function - def my_generator(): yield 1

• Exam...read more

A module is a single file of Python code, while a package is a collection of modules organized in a directory structure.

• A module is a single Python file (e.g., `math.py`).

• A package is a directory containing multiple modules and a special `__init__.py` file (e.g., `mypackage/`).

• Modules can be imported directly (e.g., `import math`).

• Packages allow for hierarchical organization of modules (e.g., `from mypackage import mymodule`).

• Packages can contain sub-packages, enabling deeper...read more

A primary key uniquely identifies a record, while a unique key ensures all values in a column are distinct but allows nulls.

• A primary key cannot contain NULL values, while a unique key can allow one NULL value.

• A table can have only one primary key, but it can have multiple unique keys.

• Example: In a 'Users' table, 'user_id' can be a primary key, while 'email' can be a unique key.

• Primary keys are often used for relationships between tables, while unique keys enforce data integr...read more

Clustered indexes sort and store data rows, while non-clustered indexes create a separate structure for quick lookups.

• Clustered indexes determine the physical order of data in a table.

• A table can have only one clustered index because data rows can be sorted in only one way.

• Non-clustered indexes maintain a separate structure that points to the data rows, allowing multiple non-clustered indexes per table.

• Example: A clustered index on a 'UserID' column sorts the table by 'UserID...read more

Accessing an HTTP URL can be done using various methods like web scraping, browser automation, or direct HTTP requests.

• Use the 'requests' library in Python to make GET or POST requests to the URL.

• Example: response = requests.get('http://example.com')

• Utilize web scraping tools like BeautifulSoup to extract data from HTML pages.

• Example: soup = BeautifulSoup(response.content, 'html.parser')

• Employ browser automation tools like Selenium to interact with web pages.

• Example: driver =...read more

Count common words in two strings by splitting, using sets, and finding intersections.

• Split both strings into lists of words using the split() method.

• Convert the lists to sets to eliminate duplicates.

• Use set intersection to find common words.

• Example: 'hello world' and 'world of python' -> common words: {'world'}.

Access specifiers in Python control the accessibility of class attributes and methods.

• Access specifiers are not explicitly defined in Python like in other languages such as Java or C++.

• By convention, attributes and methods starting with a single underscore (_) are considered 'protected' and should not be accessed directly.

• Attributes and methods starting with double underscores (__) are considered 'private' and are name-mangled to prevent direct access.

List is mutable, tuple is immutable in Python.

• List is mutable, meaning its elements can be changed after creation.

• Tuple is immutable, meaning its elements cannot be changed after creation.

• List is defined using square brackets [], tuple using parentheses ().

• Example: list_example = [1, 2, 3], tuple_example = (4, 5, 6)

Tuple is immutable, list is mutable. Lambda functions are used for small, anonymous functions.

• Tuple is immutable, cannot be changed after creation. List is mutable, can be modified.

• Tuple uses parentheses, list uses square brackets. Example: my_tuple = (1, 2, 3), my_list = [1, 2, 3]

• Lambda functions are used for small, anonymous functions. They can be used as arguments to higher-order functions. Example: lambda x: x*2

Approach scenario problems by breaking them down, analyzing requirements, and implementing solutions step-by-step.

• Identify the problem: Clearly define what the scenarios are asking.

• Break it down: Divide the problem into smaller, manageable parts.

• Analyze requirements: Understand what inputs and outputs are needed.

• Develop a plan: Outline the steps or algorithms to solve the problem.

• Implement and test: Write code for each part and test thoroughly.

Python is a high-level, interpreted programming language used for web development, data analysis, and artificial intelligence.

• Python is easy to learn and has a simple syntax

• It is widely used in web development frameworks like Django and Flask

• Python is used for data analysis and visualization with libraries like Pandas and Matplotlib

• It is also used in artificial intelligence and machine learning with libraries like TensorFlow and Scikit-learn

Create a new list with shuffled order and no duplicate elements.

• Use the random.shuffle() function to shuffle the list

• Use a set to keep track of elements already added to the new list to avoid duplicates

• Convert the set back to a list to maintain the order of elements

Python is a versatile, easy-to-learn language favored for its readability, extensive libraries, and strong community support.

• Readability: Python's syntax is clear and intuitive, making it easy for beginners to learn and for teams to collaborate.

• Extensive Libraries: Python has a rich ecosystem of libraries (e.g., NumPy for numerical computing, Pandas for data analysis) that accelerate development.

• Cross-Platform: Python runs on various platforms (Windows, macOS, Linux), allowin...read more