Python函数参数全攻略

def func(*nums):
    print(f"nums: {nums}, type: {type(nums)}")
func(1, 2, 3)          # nums: (1, 2, 3), type: <class 'tuple'>
func('a', 'b')         # nums: ('a', 'b'), type: <class 'tuple'>
func()                 # nums: (), type: <class 'tuple'>

python
def calculate_sum(*numbers):
    return sum(numbers)
print(calculate_sum(1, 2, 3))        # 6
print(calculate_sum(10, 20, 30, 40)) # 100

def func(**nums):
    print(f"nums: {nums}, type: {type(nums)}")
func(a=1, b=2, c=3)    # nums: {'a': 1, 'b': 2, 'c': 3}, type: <class 'dict'>
func(name="Alice")     # nums: {'name': 'Alice'}, type: <class 'dict'>
func()                 # nums: {}, type: <class 'dict'>

def create_user(**user_info):
    user = {
        'name': 'Unknown',
        'age': 0,
        'email': ''
    }
    user.update(user_info)  # 用传入的参数更新默认值
    return user
user1 = create_user(name="Alice", age=25)
user2 = create_user(name="Bob", email="bob@example.com")

def complex_func(required, *args, **kwargs):
    print(f"必需参数: {required}")
    print(f"可变位置参数: {args}")
    print(f"可变关键字参数: {kwargs}")
complex_func("hello", 1, 2, 3, name="Alice", age=25)
# 输出:
# 必需参数: hello
# 可变位置参数: (1, 2, 3)
# 可变关键字参数: {'name': 'Alice', 'age': 25}

def func(a, b, c):
    print(f"a={a}, b={b}, c={c}")
# 参数解包
numbers = [1, 2, 3]
func(*numbers)  # 相当于 func(1, 2, 3)
params = {'a': 10, 'b': 20, 'c': 30}
func(**params)  # 相当于 func(a=10, b=20, c=30)

def student_info(name, age, *scores, **additional_info):
    print(f"学生: {name}, 年龄: {age}")
    print(f"成绩: {scores}")
    print(f"附加信息: {additional_info}")
# 使用示例
student_info("张三", 20, 85, 90, 78, city="北京", hobby="篮球")
# 输出:
# 学生: 张三, 年龄: 20
# 成绩: (85, 90, 78)
# 附加信息: {'city': '北京', 'hobby': '篮球'}

# 这是错误的！
# def wrong_order(**kwargs, *args, a, b):
#     pass