def function_name(parameters):
    """函數(shù)文檔字符串（可選）"""
    # 函數(shù)體
    return value  # 返回值（可選）

def add(a, b):
    return a + b

result = add(3, 5)  # a=3, b=5，按位置傳遞參數(shù)

def greet(name, msg="Hello"):
    return f"{msg}, {name}!"

print(greet("Alice"))       # 使用默認值："Hello, Alice!"
print(greet("Bob", "Hi"))   # 覆蓋默認值："Hi, Bob!"

def sum_all(*args):
    return sum(args)

print(sum_all(1, 2, 3))      # 輸出: 6
print(sum_all(1, 2, 3, 4))   # 輸出: 10

def print_info(**kwargs):
    for key, value in kwargs.items():
        print(f"{key}: {value}")

print_info(name="Alice", age=30)
# 輸出:
# name: Alice
# age: 30

def complex_func(a, b=10, *args, **kwargs):
    print(f"a={a}, b=, args={args}, kwargs={kwargs}")

complex_func(1, 2, 3, 4, x=5, y=6)
# 輸出: a=1, b=2, args=(3, 4), kwargs={'x': 5, 'y': 6}

def calculate(a, b):
    return a + b, a - b, a * b  # 返回多個值

sum_result, diff_result, prod_result = calculate(5, 3)
print(sum_result)   # 輸出: 8
print(diff_result)  # 輸出: 2
print(prod_result)  # 輸出: 15

def reverse_string(s):
    return s[::-1]

print(reverse_string("hello"))  # 輸出: "olleh"

def is_prime(num):
    if num < 2:
        return False
    for i in range(2, int(num ** 0.5) + 1):
        if num % i == 0:
            return False
    return True

print(is_prime(7))   # 輸出: True
print(is_prime(8))   # 輸出: False

def read_file(filename):
    try:
        with open(filename, 'r') as f:
            return f.read()
    except FileNotFoundError:
        return None

content = read_file("data.txt")
if content:
    print(content)
else:
    print("文件不存在")

def apply_operation(func, a, b):
    return func(a, b)

def multiply(x, y):
    return x * y

result = apply_operation(multiply, 3, 4)
print(result)  # 輸出: 12

def test():
    x = 10
print(x)  # 報錯：NameError

def append_value(value, lst=[]):  # 錯誤示例
    lst.append(value)
    return lst

print(append_value(1))  # 輸出: [1]
print(append_value(2))  # 輸出: [1, 2]（非預期）

def append_value(value, lst=None):
    if lst is None:
        lst = []
    lst.append(value)
    return lst

def my_func():
    """這是一個示例函數(shù)"""
    pass

print(my_func.__doc__)  # 輸出: "這是一個示例函數(shù)"

square = lambda x: x ** 2
print(square(5))  # 輸出: 25

def timer_decorator(func):
    import time
    def wrapper(*args, **kwargs):
        start_time = time.time()
        result = func(*args, **kwargs)
        print(f"函數(shù)運行時間: {time.time() - start_time}秒")
        return result
    return wrapper

@timer_decorator
def heavy_computation(n):
    return sum(i*i for i in range(n))

heavy_computation(1000000)  # 輸出運行時間