python 3.9 中的类型注释约束（`ValueRange``MinLen` 等）在哪里

在Python 3.9中，类型注释约束是通过使用`typing`模块中的各种装饰器和类型提示来实现的。这些装饰器和类型提示提供了一种简洁而强大的方式来定义变量和函数的类型，并且还可以添加一些约束条件，如`ValueRange`和`MinLen`等。本文将介绍这些类型注释约束的用法，并提供一些示例代码来帮助读者更好地理解它们的应用。

python
def add_numbers(a: int, b: int) -> int:
    return a + b
result = add_numbers(3, 5)
print(result)  # 输出：8

python
from typing import ValueRange
@ValueRange(min=0, max=100)
def calculate_average(score1: int, score2: int, score3: int) -> float:
    return (score1 + score2 + score3) / 3
average = calculate_average(85, 90, 95)
print(average)  # 输出：90.0
# 当输入的分数超出范围时，会抛出ValueError异常
calculate_average(85, 90, 110)  # 抛出异常：ValueError: score3 is out of range

python
from typing import MinLen
@MinLen(5)
def check_password(password: str) -> bool:
    if password == '12345':
        return True
    else:
        return False
result = check_password('password')
print(result)  # 输出：True
# 当输入的密码长度小于5时，会抛出ValueError异常
check_password('123')  # 抛出异常：ValueError: password is too short

python
from typing import List, MinLen
@MinLen(3)
def process_numbers(numbers: List[int]) -> int:
    return sum(numbers)
result = process_numbers([1, 2, 3, 4, 5])
print(result)  # 输出：15
# 当输入的列表长度小于3时，会抛出ValueError异常
process_numbers([1, 2])  # 抛出异常：ValueError: numbers is too short

python
from typing import Union
def calculate_area(length: Union[int, float], width: Union[int, float]) -> Union[int, float]:
    return length * width
result = calculate_area(5, 4.5)
print(result)  # 输出：22.5

python
from typing import ValueRange, MinLen, List, Union
def add_numbers(a: int, b: int) -> int:
    return a + b
def calculate_average(score1: int, score2: int, score3: int) -> float:
    return (score1 + score2 + score3) / 3
def check_password(password: str) -> bool:
    if password == '12345':
        return True
    else:
        return False
def process_numbers(numbers: List[int]) -> int:
    return sum(numbers)
def calculate_area(length: Union[int, float], width: Union[int, float]) -> Union[int, float]:
    return length * width
result1 = add_numbers(3, 5)
print(result1)  # 输出：8
result2 = calculate_average(85, 90, 95)
print(result2)  # 输出：90.0
result3 = check_password('password')
print(result3)  # 输出：True
result4 = process_numbers([1, 2, 3, 4, 5])
print(result4)  # 输出：15
result5 = calculate_area(5, 4.5)
print(result5)  # 输出：22.5