Master Python Intermediate Topics in Week 2

Week 2: Intermediate Python Topics (Days 8–14)

After mastering the Python basics in Week 1, it’s time to level up your skills! Week 2 introduces intermediate concepts like error handling, object-oriented programming (OOP), file handling, and more. These topics will help you build real-world Python applications and improve your problem-solving abilities.

---

Day 8: Error Handling in Python

On Day 8, you will learn how to handle errors in Python using try, except, and finally. Proper error handling ensures that your programs run smoothly even when unexpected situations arise.

• What to learn:
• Understand how to handle exceptions with try, except, and else.
• Use finally for cleanup code.
• Explore built-in exceptions like ValueError, IndexError, and FileNotFoundError.

  try:
      number = int(input("Enter a number: "))
      print(f"You entered: {number}")
  except ValueError:
      print("Invalid input, please enter a valid number.")
  finally:
      print("Execution finished.")

---

Day 9: Object-Oriented Programming (OOP) Basics

On Day 9, you’ll dive into Object-Oriented Programming (OOP), which is a key concept in Python and many other programming languages. Learn to create classes and objects, and understand the concepts of inheritance and encapsulation.

• What to learn:
• Define classes and create objects.
• Understand methods and attributes.
• Learn about inheritance, constructors (__init__), and method overriding.

  class Dog:
      def __init__(self, name, breed):
          self.name = name
          self.breed = breed

      def speak(self):
          print(f"{self.name} says woof!")

  my_dog = Dog("Buddy", "Golden Retriever")
  my_dog.speak()  # Output: Buddy says woof!

---

Day 10: Working with Files in Python

Day 10 covers file handling in Python. Learn how to read, write, and manage files effectively. This is essential for creating applications that interact with external data.

• What to learn:
• Open, read, and write to files using open(), read(), and write().
• Understand file modes ('r', 'w', 'a').
• Practice reading and writing text and binary files.

  # Writing to a file
  with open("example.txt", "w") as file:
      file.write("Hello, Python!")

  # Reading from a file
  with open("example.txt", "r") as file:
      content = file.read()
      print(content)  # Output: Hello, Python!

---

Day 11: List Comprehensions and Lambda Functions

On Day 11, you’ll learn about list comprehensions and lambda functions, which help simplify your code and make it more efficient.

• What to learn:
• Write concise list comprehensions to filter and transform data.
• Use lambda for creating anonymous functions.

  # List comprehension
  numbers = [1, 2, 3, 4, 5]
  squared_numbers = [x**2 for x in numbers]
  print(squared_numbers)  # Output: [1, 4, 9, 16, 25]

  # Lambda function
  square = lambda x: x**2
  print(square(5))  # Output: 25

---

Day 12: Working with Modules and Packages

Learn how to organize your code by creating and importing modules and packages. This helps you structure your projects and reuse code efficiently.

• What to learn:
• Create custom Python modules and import them.
• Learn how to use the import statement.
• Explore standard library modules like math, datetime, and random.

  # my_module.py
  def greet(name):
      return f"Hello, {name}!"

  # main.py
  import my_module
  print(my_module.greet("Alice"))

---

Day 13: Iterators and Generators

On Day 13, you’ll learn about iterators and generators. These are useful for managing large data sets and controlling the flow of data in your programs.

• What to learn:
• Create custom iterators using __iter__() and __next__().
• Use generators with yield to create lazy iterators.

  # Iterator example
  class CountUp:
      def __init__(self, low, high):
          self.current = low
          self.high = high

      def __iter__(self):
          return self

      def __next__(self):
          if self.current > self.high:
              raise StopIteration
          else:
              self.current += 1
              return self.current - 1

  for number in CountUp(1, 5):
      print(number)

  # Generator example
  def count_up_to(n):
      count = 1
      while count <= n:
          yield count
          count += 1

  for number in count_up_to(5):
      print(number)

---

Day 14: Regular Expressions (Regex)

On Day 14, you’ll explore regular expressions, which allow you to search, match, and manipulate strings based on specific patterns.

• What to learn:
• Use the re module to work with regular expressions.
• Match patterns in strings with re.match(), re.search(), and re.findall().

  import re
  text = "The rain in Spain stays mainly in the plain."
  result = re.findall(r"\bin\b", text)
  print(result)  # Output: ['in', 'in', 'in']

---

Conclusion of Week 2

By the end of Week 2, you’ll have gained a deeper understanding of Python’s intermediate concepts, including error handling, object-oriented programming, file handling, and regular expressions. These skills will enable you to write more sophisticated programs and tackle real-world problems.

---

Next Steps

In Week 3, you will move on to advanced topics such as advanced object-oriented programming, testing, and working with Python’s standard libraries. Keep practicing and building projects to reinforce your knowledge!