Simple if/else Expressions

Now that we're acquainted with conditional operators and know how to use them, we can branch our code based on certain conditions. In Python, this is achieved with the following structure:

In the example above, the condition can be either a conditional statement or a boolean value. For example, it might look like a != 4 or b > 100. The commands beneath if and else are instructions to be executed depending on whether the condition is met. These could be print() functions, variable assignments, arithmetic operations, string manipulations, and more.

Let's walk through an example: Suppose you have a string and you want to determine if it's long. We'll define a string as 'long' if it contains more than 20 characters.


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# Assign some variable
test = "small string"

# Conditional statement
if len(test) > 20:
    print("This string is long!")
else:
    print("Nothing special")
    
# Check on different string
test = "This string is very-very and very large"

# Conditional statement
if len(test) > 20:
    print("This string is long!")
else:
    print("Nothing special")

Note

Remember, the code blocks under the if and else statements should have consistent indentation (e.g., 2 spaces, 4 spaces, etc.).

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Section 3. Chapter 6