What is the usage of if-else statements in Python?

In Python, the if-else statement is used to execute different code blocks based on conditions. The syntax is as follows:

if 条件:
    # 条件为真时执行的代码块
else:
    # 条件为假时执行的代码块

In this syntax structure, if the condition is true, the code block under the if statement will be executed; if the condition is false, the code block under the else statement will be executed. Depending on specific needs, you can choose whether or not to include the else statement, or use nested if statements to evaluate multiple conditions.