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Module 35 - Interview Prep & Career

Prepare for Python interviews with common questions, coding challenges, and career advice.

1. Common Interview Questions​

What is Python?​

Python is a high-level, interpreted, general-purpose programming language known for its simplicity and readability.

What are Python's key features?​

  • Easy to learn and read
  • Interpreted language
  • Dynamically typed
  • Object-oriented
  • Large standard library
  • Cross-platform

What is PEP 8?​

PEP 8 is the official style guide for Python code, providing conventions for code formatting and naming.

2. Data Structures Questions​

Lists vs Tuples​

# List (mutable)
my_list = [1, 2, 3]
my_list[0] = 10  # OK

# Tuple (immutable)
my_tuple = (1, 2, 3)
# my_tuple[0] = 10  # Error!

Dictionary Methods​

d = {'a': 1, 'b': 2}

# Get value
print(d.get('a'))  # 1
print(d.get('c', 0))  # 0 (default)

# Keys, values, items
print(d.keys())    # dict_keys(['a', 'b'])
print(d.values())  # dict_values([1, 2])
print(d.items())   # dict_items([('a', 1), ('b', 2)])

3. OOP Questions​

Inheritance​

class Animal:
    def speak(self):
        pass

class Dog(Animal):
    def speak(self):
        return "Woof!"

class Cat(Animal):
    def speak(self):
        return "Meow!"

Class vs Instance Variables​

class MyClass:
    class_var = "shared"  # Class variable
    
    def __init__(self, instance_var):
        self.instance_var = instance_var  # Instance variable

4. Common Coding Challenges​

Reverse a String​

def reverse_string(s):
    return s[::-1]

# Alternative
def reverse_string_manual(s):
    return ''.join(reversed(s))

Check if Palindrome​

def is_palindrome(s):
    s = s.lower().replace(' ', '')
    return s == s[::-1]

print(is_palindrome("A man a plan a canal Panama"))  # True

FizzBuzz​

def fizzbuzz(n):
    for i in range(1, n + 1):
        if i % 15 == 0:
            print("FizzBuzz")
        elif i % 3 == 0:
            print("Fizz")
        elif i % 5 == 0:
            print("Buzz")
        else:
            print(i)

Find Duplicates​

def find_duplicates(lst):
    seen = set()
    duplicates = set()
    
    for item in lst:
        if item in seen:
            duplicates.add(item)
        seen.add(item)
    
    return list(duplicates)

print(find_duplicates([1, 2, 3, 2, 4, 5, 3]))  # [2, 3]

Two Sum Problem​

def two_sum(nums, target):
    seen = {}
    for i, num in enumerate(nums):
        complement = target - num
        if complement in seen:
            return [seen[complement], i]
        seen[num] = i
    return []

print(two_sum([2, 7, 11, 15], 9))  # [0, 1]

5. Algorithm Questions​

def binary_search(arr, target):
    left, right = 0, len(arr) - 1
    
    while left <= right:
        mid = (left + right) // 2
        if arr[mid] == target:
            return mid
        elif arr[mid] < target:
            left = mid + 1
        else:
            right = mid - 1
    
    return -1

Merge Two Sorted Arrays​

def merge_sorted_arrays(arr1, arr2):
    result = []
    i = j = 0
    
    while i < len(arr1) and j < len(arr2):
        if arr1[i] < arr2[j]:
            result.append(arr1[i])
            i += 1
        else:
            result.append(arr2[j])
            j += 1
    
    result.extend(arr1[i:])
    result.extend(arr2[j:])
    
    return result

6. Advanced Topics Questions​

Decorators​

def timer_decorator(func):
    import time
    def wrapper(*args, **kwargs):
        start = time.time()
        result = func(*args, **kwargs)
        end = time.time()
        print(f"{func.__name__} took {end-start:.4f}s")
        return result
    return wrapper

@timer_decorator
def slow_function():
    time.sleep(1)

Generators​

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

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

Context Managers​

class FileManager:
    def __init__(self, filename, mode):
        self.filename = filename
        self.mode = mode
    
    def __enter__(self):
        self.file = open(self.filename, self.mode)
        return self.file
    
    def __exit__(self, exc_type, exc_value, traceback):
        self.file.close()

with FileManager('test.txt', 'w') as f:
    f.write('Hello!')

7. System Design Questions​

Design a URL Shortener​

  • Generate unique short codes
  • Store mapping in database
  • Redirect to original URL
  • Track analytics

Design a Cache System​

from collections import OrderedDict

class LRUCache:
    def __init__(self, capacity):
        self.cache = OrderedDict()
        self.capacity = capacity
    
    def get(self, key):
        if key not in self.cache:
            return -1
        self.cache.move_to_end(key)
        return self.cache[key]
    
    def put(self, key, value):
        if key in self.cache:
            self.cache.move_to_end(key)
        self.cache[key] = value
        if len(self.cache) > self.capacity:
            self.cache.popitem(last=False)

8. Behavioral Questions​

Tell me about yourself​

  • Brief background
  • Current role/education
  • Why Python/programming
  • Career goals

Describe a challenging project​

  • Situation
  • Task
  • Action
  • Result (STAR method)

9. Interview Tips​

Before the Interview​

✅ Research the company
✅ Review job description
✅ Practice coding problems
✅ Prepare questions to ask
✅ Test your setup (for remote)

During the Interview​

✅ Think out loud
✅ Ask clarifying questions
✅ Start with simple solution
✅ Test your code
✅ Discuss trade-offs

After the Interview​

✅ Send thank-you email
✅ Reflect on performance
✅ Follow up if needed

10. Career Resources​

Learning Platforms​

  • LeetCode: Coding challenges
  • HackerRank: Practice problems
  • Real Python: Tutorials
  • Python.org: Official documentation

Communities​

  • Stack Overflow: Q&A
  • Reddit (r/Python, r/learnpython)
  • Discord: Python communities
  • LinkedIn: Professional networking

Certifications​

  • Python Institute (PCAP, PCPP)
  • AWS Certified Developer
  • Google Python Certification

11. Salary Negotiation Tips​

✅ Research market rates
✅ Know your worth
✅ Consider total compensation
✅ Be prepared to justify
✅ Don't accept first offer immediately
✅ Get it in writing

12. Building Your Portfolio​

GitHub Profile​

  • Pin best projects
  • Write clear README files
  • Contribute to open source
  • Show commit history

Personal Projects​

  • Web applications
  • Data analysis projects
  • Automation tools
  • APIs and microservices

Blog/Technical Writing​

  • Document learnings
  • Tutorial articles
  • Project case studies

13. Job Search Strategy​

Where to Look​

  • LinkedIn
  • Indeed
  • Glassdoor
  • AngelList (startups)
  • Company career pages
  • Networking events

Resume Tips​

✅ Tailor to job description
✅ Highlight Python projects
✅ Quantify achievements
✅ Include relevant skills
✅ Keep it concise (1-2 pages)

14. Practice Problems​

Easy​

  1. Reverse a string
  2. Check if palindrome
  3. Find maximum in array
  4. Count vowels in string
  5. Remove duplicates from list

Medium​

  1. Implement binary search
  2. Merge two sorted arrays
  3. Validate parentheses
  4. Find longest substring without repeating characters
  5. Group anagrams

Hard​

  1. Median of two sorted arrays
  2. Regular expression matching
  3. Trapping rain water
  4. N-Queens problem
  5. Word ladder

15. Final Tips for Success​

✅ Practice regularly: Code every day
✅ Read others' code: Learn from open source
✅ Build projects: Apply what you learn
✅ Stay updated: Follow Python news
✅ Network: Attend meetups, conferences
✅ Teach others: Solidify your understanding
✅ Never stop learning: Technology evolves

Summary​

✅ Master fundamental concepts
✅ Practice coding challenges regularly
✅ Understand data structures and algorithms
✅ Build a strong portfolio
✅ Prepare for behavioral questions
✅ Network and stay engaged
✅ Keep learning and improving

Congratulations! 🎉​

You've completed all 35 Python modules! You now have a solid foundation in:

  • Python fundamentals
  • Advanced features
  • Web development
  • Data science basics
  • Best practices
  • Interview preparation

Next Steps:​

  1. Build real-world projects
  2. Contribute to open source
  3. Specialize in an area (web, data science, ML, etc.)
  4. Keep practicing and learning
  5. Share your knowledge with others

Good luck with your Python journey! 🐍