python if else finally

在Python中，if-else语句用于根据条件执行不同的代码块。finally子句用于定义无论是否发生异常都会执行的代码块。下面是一个示例：

try:
    # 代码块
    age = int(input('请输入你的年龄：'))
    if age >= 18:
        print('你已经成年了')
    else:
        print('你还没有成年')
except:
    # 异常处理代码块
    print('发生了异常')
finally:
    # 无论是否发生异常都会执行的代码块
    print('程序执行完毕')

在上面的示例中，我们使用try-except语句来捕获可能发生的异常。如果用户输入的不是一个整数，会触发异常并执行except代码块中的代码。无论是否发生异常，finally代码块中的代码都会执行。

相关问题

python 中的if else finally语法结构

在 Python 中，if-else-finally 是一种条件语句结构，用于根据条件执行不同的代码块。if-else-finally 语法结构如下：

if condition:
    # 如果条件为真，执行这个代码块
else:
    # 如果条件为假，执行这个代码块
finally:
    # 不管条件是否为真，都会执行这个代码块

其中 `condition` 是待测试的条件，可以是任何能够返回 True 或 False 的表达式。如果条件为真，将执行 `if` 代码块；否则，将执行 `else` 代码块。无论条件是否为真，都会执行 `finally` 代码块。

需要注意的是，如果 `if` 代码块只有一行语句，可以写成一行，如下所示：

if condition: statement

如果 `else` 或 `finally` 代码块只有一行语句，也可以写成一行。

python if

In Python, `if` is a conditional statement that allows you to execute a block of code only if a certain condition is met. Here's the basic syntax of an `if` statement:

if condition:
    # code to execute if condition is True

The `condition` can be any expression that evaluates to a Boolean value (`True` or `False`). If the `condition` is `True`, the code block indented under the `if` statement will be executed. If the `condition` is `False`, the code block will be skipped and execution will continue with the next statement after the `if` block.

You can also use an `else` statement to specify a block of code to execute if the `condition` is `False`:

if condition:
    # code to execute if condition is True
else:
    # code to execute if condition is False

Finally, you can use an `elif` statement (short for "else if") to specify additional conditions to check:

if condition1:
    # code to execute if condition1 is True
elif condition2:
    # code to execute if condition2 is True and condition1 is False
else:
    # code to execute if both condition1 and condition2 are False

Here's an example to help illustrate how `if` statements work:

x = 5

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

In this example, the `condition` is `x > 0`. Since `x` is equal to `5`, which is greater than `0`, the code block under the `if` statement will be executed, and the output will be:

x is positive

I hope this helps! Let me know if you have any other questions.