Python Basics 2

This post is exploring the basics of Python

Conditional Statements: The Art of Decision-Making in Python

Imagine a robot that has to choose its next move based on a series of clues. It might need to check if the room is bright enough for it to see, or if there’s an obstacle ahead. This decision-making process is called conditional logic, and in programming, we use “if” statements to implement this very logic!

In Python, conditional statements are key tools for making decisions based on certain conditions. Let’s break down the basics:

1. The Basic Structure:

if condition_true:
    # Code to execute if the condition is true
else:
    # Code to execute if the condition is false

• condition_true: This is a Boolean expression that evaluates to either True or False. It’s what we use to decide which code block should run.
• # Code to execute if the condition is true: You put the statements that you want to be executed only if the condition_true evaluates to True.
• else: This optional block executes if the initial if statement’s condition_true was False.

2. Understanding the “If” Statement:

• Python compares different values using symbols like:
  • ==: checks for equality (e.g., 5 == 5 is True)
  • !=: checks for inequality (e.g., 5 != 6 is True)
  • <: checks for less-than
  • >: checks for greater-than

3. Combining “If” and “Else” to Get More Complex Decisions:

• You can have multiple if statements, each with its own condition_true. This allows you to create more intricate decision paths:

4. The Power of “elif” (Else If):

• Sometimes, your initial if condition might be false, but there are other possibilities you want to check with more specific conditions.
  That’s where elif comes in:

5. The “elif” Statement’s Purpose:

• The elif statement allows you to check multiple conditions sequentially, giving more flexibility in your decision-making process, especially when the initial condition might be false.

6. Practice Makes Perfect!

• The best way to get comfortable with conditional statements is by practicing:
  • Start with simple examples to solidify your understanding.
  • Gradually increase the complexity of your decisions and explore more if-elif-else logic combinations.

Another Simple Example: Did a student pass?

Checking if a student passed, based on their points scored. Try chaning the number of points a student scored and see the result.

Explanation:

1. Input:
   • points = int(70)
     • This line inputs the points as an integer
2. Conditional Statement:
   • if points >= 70:: We use an if statement to check if the entered points is greater than or equal to 70.
     
   • print("Congratulations! You passed!"): If the condition is true (points ≥ 70), this message will be printed, indicating a passing points.
   • else:: If the condition is false, we enter an else block.
   • print(f"You're missing some studying. Try again next time!"): This message will be printed if the student did not pass the course.
3. Result: This code gives us a basic structure to check for passing points based on a specific threshold (70). You can adjust this threshold (or check for other points) as needed!

How It Works: - The code checks whether the points is greater than or equal to 70. - If the condition (points >= 70) is true, it prints “Congratulations! You passed!”. - If the condition is false, it prints a message suggesting that the student needs to study harder and try again.

Additional Notes: - You can easily add more points and different logic for if statements within this code block as needed. - This example demonstrates basic conditional statement functionality in Python.

Here are some more examples:

elif Example: Clothing Selection

A slightly more complex example of using conditional statements using if, elif and else.

Try running the code below by changing the input to size variable.

• Explanation: We first try to match the user’s input to specific sizes (XS, S, M, L, XL, XXL)
• elif: If no match is found in the if block, Python checks the next condition (elif).
• if the input does not match any condition, else is used to print the output.