2.1. Conditions and if statements

In previous sections, you have acquired essential skills in Python such as variable creation, operator utilization, and code analysis. These skills enable you to accomplish a wide range of tasks. However, there is still a need for increased flexibility. Manually modifying your code to accommodate different data and reverting those changes can be cumbersome. In this section, you will delve into the concept of code control, which allows you to navigate the execution of your code based on specific conditions. To achieve this, you will explore a fundamental programming construct called the if statement. Through this construct, you will gain the ability to selectively process data based on defined conditions, enhancing the adaptability and efficiency of your code.

We have three sections:

• If Statement: The if statement enables us to execute a block of code only if a specified condition is true. It provides a way to make decisions and selectively perform actions based on whether a condition evaluates to true or false.

• Elif Statement: The elif statement allows us to consider multiple conditions one after another and execute different blocks of code based on the first condition that evaluates to true. It provides a means to handle various possibilities and choose the appropriate action based on the situation.

• If-else Statement: The if-else statement combines the if and else statements to perform one action if a condition is true and a different action if the condition is false. It offers a way to provide alternative paths of execution, ensuring that the code responds differently based on whether a condition is met or not.

These conditional statements allow you to make decisions and control the flow of your program based on specific conditions. For example like this:

x = 5
if x > 0:
    print("x is positive")

x = -2
if x > 0:
    print("x is positive")
else:
    print("x is non-positive")

x = 0
if x > 0:
    print("x is positive")
elif x < 0:
    print("x is negative")
else:
    print("x is zero")

x is positive
x is non-positive
x is zero