Interview Questions and Answers

List comprehension is a concise way to create lists in Python by iterating over an existing list or iterable.

• List comprehension is more concise and readable than traditional loops.

• It can be used to filter elements, perform operations on elements, or create new lists based on existing ones.

• Example: squares = [x**2 for x in range(10)]

• Example: even_numbers = [x for x in range(10) if x % 2 == 0]

A dictionary in Python is a collection of key-value pairs. It does not accept duplicate keys.

• A dictionary is created using curly braces {}

• Keys in a dictionary must be unique, but values can be duplicated

• Example: my_dict = {'name': 'John', 'age': 30, 'city': 'New York'}

A generator in Python is a function that returns an iterator object which can be iterated over to generate values lazily.

• Generators are created using a function with 'yield' keyword instead of 'return'.

• They allow for efficient memory usage as they generate values on the fly.

• Generators are useful for generating large sequences of data without storing them in memory.

• Example: def my_generator(): for i in range(5): yield i

• Example: gen = my_generator() for value in gen: print(valu...read more

Main principles of OOP include encapsulation, inheritance, polymorphism, and abstraction.

• Encapsulation: Bundling data and methods that operate on the data into a single unit (class). Example: Class with private attributes and public methods.

• Inheritance: Ability to create a new class (derived class) from an existing class (base class), inheriting its attributes and methods. Example: Subclass 'Dog' inheriting from superclass 'Animal'.

• Polymorphism: Ability for objects of differe...read more

Fibonacci series is a sequence of numbers where each number is the sum of the two preceding ones.

• Initialize variables for the first two numbers in the series (0 and 1)

• Use a loop to calculate the next number by adding the previous two numbers

• Continue the loop until the desired number of terms is reached

AWS Lambda is a serverless computing service provided by Amazon Web Services.

• Serverless computing service

• Allows running code without provisioning or managing servers

• Automatically scales based on incoming traffic

• Supports multiple programming languages like Python, Node.js, Java, etc.

• Pay only for the compute time consumed

Decorator is a design pattern in Python that allows adding new functionality to an existing object without modifying its structure.

• Decorators are functions that take another function as an argument and extend its behavior without modifying it directly.

• They are commonly used to add logging, timing, caching, or authentication to functions.

• Decorators use the @ symbol followed by the decorator name above the function definition.

• Example: @decorator_name def function_name(): pass

List is mutable, tuple is immutable in Python.

• List can be modified after creation, tuple cannot.

• List uses square brackets [], tuple uses parentheses ().

• List is used for dynamic data, tuple for fixed data.

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