Python If…Else

In Python, the if...else statement allows you to control the flow of your program based on certain conditions. It allows you to specify different blocks of code to be executed depending on whether a condition is true or false.

The basic syntax of the if...else statement in Python is as follows:

python

if condition:
    # block of code to be executed if the condition is true
else:
    # block of code to be executed if the condition is false

Here’s a simple example that demonstrates the usage of if...else:

python

x = 10

if x > 0:
    print("x is positive")
else:
    print("x is zero or negative")

In this example, if the condition x > 0 is true, the statement print("x is positive") will be executed. Otherwise, if the condition is false, the statement print("x is zero or negative") will be executed.

You can also use multiple elif (short for “else if”) statements to check additional conditions. Here’s an example:

python

x = 10

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

In this case, if x is greater than 0, the first block of code will be executed. If x is equal to 0, the second block of code will be executed. Otherwise, if none of the conditions are true, the last block of code will be executed.

Remember to indent the code blocks consistently using spaces or tabs. The indentation is crucial in Python because it defines the scope of the code within each block.

You can also nest if...else statements within each other to create more complex conditional logic. However, it’s important to keep the code readable and avoid excessive nesting for clarity.