Python’s simplicity and versatility make it a popular choice for both beginners and experienced developers. If you’re preparing for an entry-level Python interview, these essential questions and answers will help you make a strong impression.
1. What is Python, and what are its key features?
Answer:
Python is a high-level, interpreted programming language known for its simplicity and readability. Its key features include:
- Easy Syntax: Resembles plain English, making it beginner-friendly.
- Interpreted Language: Executes code line-by-line without compilation.
- Object-Oriented: Supports OOP concepts like classes and objects.
- Cross-Platform: Works on Windows, macOS, Linux, etc.
- Extensive Libraries: Includes libraries like NumPy, Pandas, and TensorFlow.
2. What are lists and tuples in Python?
Answer:
- Lists: Mutable, ordered collections that can be changed after creation. Defined with square brackets:
my_list = [1, 2, 3] - Tuples: Immutable, ordered collections that cannot be changed after creation. Defined with parentheses:
my_tuple = (1, 2, 3)
3. How is memory managed in Python?
Answer:
Python uses an automatic memory management system with:
- Garbage Collection: Reclaims unused memory.
- Reference Counting: Tracks object references to deallocate memory when count reaches zero.
4. Explain Python’s type of language: interpreted or compiled?
Answer:
Python is an interpreted language, meaning code is executed line-by-line by the Python interpreter, without prior compilation.
5. What is PEP 8 and why is it important?
Answer:
PEP 8 is Python’s style guide, ensuring readability and consistency in code by defining best practices for naming conventions, indentation, and more.
6. How do you install packages in Python?
Answer:
Use the pip command in the terminal:
pip install package_name
7. What is a virtual environment in Python?
Answer:
A virtual environment is an isolated Python environment for projects to manage dependencies without affecting other projects.
Create a virtual environment:
python -m venv myenv
Answer:
Decorators are functions that modify the behavior of other functions. They are used to add functionality to an existing code.
Example:
def my_decorator(func):
def wrapper():
print("Before the function")
func()
print("After the function")
return wrapper
9. Explain the difference between ‘==’ and ‘is’ in Python.
Answer:
==checks if values of two variables are equal.ischecks if two variables refer to the same object in memory.
10. How to handle exceptions in Python?
Answer:
Use try-except blocks:
try:
print(10 / 0)
except ZeroDivisionError:
print("Cannot divide by zero")
11. What are Lambda functions in Python?
Answer:
Lambda functions are anonymous functions defined using the lambda keyword.
Example:
square = lambda x: x * x
print(square(5)) # Output: 25
12. How do you open and read a file in Python?
Answer:
with open('file.txt', 'r') as file:
content = file.read()
print(content)
13. What is the difference between append() and extend() in lists?
Answer:
append()adds a single element to the end of the list.extend()adds multiple elements (or another list) to the list.
14. Explain list comprehension with an example.
Answer:
List comprehension provides a concise way to create lists.
Example:
squares = [x**2 for x in range(5)]
print(squares) # Output: [0, 1, 4, 9, 16]
15. What are modules and packages in Python?
Answer:
- Modules: Files containing Python code (.py) that can be imported.
- Packages: Directories containing multiple modules and an
__init__.pyfile to indicate it’s a package.
Conclusion
These questions cover fundamental Python concepts, preparing you for common topics discussed in entry-level interviews. Mastering them will boost your confidence and help you demonstrate your Python skills effectively. Good luck with your interview prep!
