How to use conditional statements in Python?

Conditional statements in the Python language are an important programming concept that are often used to control the flow of the program and determine whether to perform different operations under different circumstances. In Python, commonly used conditional statements include if statements and if-else statements. This article will introduce how to use conditional statements in Python.

1. Basic usage of if statement
The if statement is one of the most commonly used conditional statements in Python. It is used to execute a block of code under specific conditions. The basic syntax is as follows:

if condition:

# 执行当条件为真时执行的代码块

where condition is a Python expression, which can be a comparison statement, logical operator or other expression that can return a Boolean value . When condition is true, the subsequent code block is executed, otherwise the code block is skipped.

The following is a simple example:

x = 10
if x > 5:
    print("x > 5")

In this example, the condition x > 5 is true, so the print statement is executed and x > 5 is output. Note that in Python, code blocks are implemented by indentation, so the code block after the if statement must be indented.

2. How to use the if-else statement
The if statement can only judge one condition. If you need to execute different code blocks under different circumstances, you can use the if-else statement. The basic syntax is as follows:

if condition:

# 执行当条件为真时执行的代码块

else:

# 执行当条件为假时执行的代码块

The else statement can be omitted. The code block after the if statement is executed when the condition is true, otherwise the code block after the else statement is executed.

The following is an example:

x = 10
if x > 15:
    print("x > 15")
else:
    print("x <= 15")

In this example, because x > 15 is not true, the code block after the else statement is executed and x 1a31af42cab48f89a5e78487e6b706a2 5 is true, the code block after the elif statement is executed and 5 e1a4b01161de58c38c2d66f1e961f836 5 and y > 3", otherwise output "x > 5 and y <= 3". If x <= 5, then output "x <= 5".

Conclusion:
This article introduces the basic syntax and usage of conditional statements in Python, including if statements, if-else statements, if-elif-else statements and nested conditional statements. Conditional statements in Python can make the program run more flexibly and smoothly. They are often used to control the flow of the program and determine how to perform different operations under different circumstances.

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