Python Interview Questions & Answers | Python Interview Preparation | Python Training

Introduction

This tutorial aims to prepare you for Python interviews by addressing some of the most frequently asked questions. Understanding these concepts will not only help you during interviews but also strengthen your overall Python knowledge.

Step 1: Understand the Differences Between List and Tuple

• List:

  • Mutable: You can modify it (add, remove, change elements).
  • Syntax: Defined by square brackets, e.g., my_list = [1, 2, 3].

• Tuple:

  • Immutable: Once defined, you cannot change it.
  • Syntax: Defined by parentheses, e.g., my_tuple = (1, 2, 3).

Practical Tip

Use lists when you need a collection of items that will change, and tuples when you want a fixed collection.

Step 2: Write a Generator Function for Fibonacci Series

A generator function allows you to iterate through a sequence without storing the entire sequence in memory.

Code Example

def fibonacci(n):
    a, b = 0, 1
    for _ in range(n):
        yield a
        a, b = b, a + b

# Usage
for num in fibonacci(10):
    print(num)

Step 3: Reverse a List in Python

You can reverse a list using various methods:

• Using the reverse() method:

my_list = [1, 2, 3]
my_list.reverse()
print(my_list)  # Output: [3, 2, 1]

• Using slicing:

my_list = [1, 2, 3]
reversed_list = my_list[::-1]
print(reversed_list)  # Output: [3, 2, 1]

Step 4: Get Current System Date and Time

You can use the datetime module for this:

Code Example

from datetime import datetime

current_time = datetime.now()
print(current_time)

Step 5: Validate an Email ID

You can use regular expressions to validate an email address.

Code Example

import re

def is_valid_email(email):
    pattern = r'^[a-zA-Z0-9_.+-]+@[a-zA-Z0-9-]+\.[a-zA-Z0-9-.]+$'
    return re.match(pattern, email) is not None

# Usage
print(is_valid_email("test@example.com"))  # Output: True

Step 6: Understand Anonymous Functions or Lambda Functions

• Lambda Functions: Small anonymous functions defined with the lambda keyword.
• Usage: Commonly used for short, throwaway functions.

Code Example

add = lambda x, y: x + y
print(add(5, 3))  # Output: 8

Step 7: Learn About the OS Module

The os module provides a way to use operating system-dependent functionality like reading or writing to the file system.

Practical Applications

• Navigating directories
• Working with environment variables
• Executing system commands

Step 8: Read a File with Multiple Lines

You can read a file and split its contents into lines and words.

Code Example

with open('file.txt', 'r') as file:
    lines = file.readlines()

# Split into words
for line in lines:
    words = line.split()
    print(words)

Step 9: Merge One Dictionary with Another

You can combine dictionaries using the update() method or the ** unpacking technique.

Code Example

dict1 = {'a': 1, 'b': 2}
dict2 = {'b': 3, 'c': 4}

# Using update
dict1.update(dict2)
print(dict1)  # Output: {'a': 1, 'b': 3, 'c': 4}

# Using unpacking
merged_dict = {**dict1, **dict2}
print(merged_dict)  # Output: {'a': 1, 'b': 3, 'c': 4}

Step 10: Remove Duplicates from a List

You can remove duplicates by converting the list to a set.

Code Example

my_list = [1, 2, 2, 3, 4, 4]
unique_list = list(set(my_list))
print(unique_list)  # Output: [1, 2, 3, 4]

Conclusion

This tutorial covered essential Python interview questions and their solutions, including the differences between lists and tuples, creating a Fibonacci generator, validating email addresses, and more. Review these concepts regularly to improve your Python skills and boost your confidence for upcoming interviews. Consider practicing these examples in your local environment to solidify your understanding.