Python 引用不确定的函数

def add(x, y):      """执行加法操作"""      return x + y    def subtract(x, y):      """执行减法操作"""      return x - y    def multiply(x, y):      """执行乘法操作"""      return x * y    # 将函数名映射到函数对象  operations = {      'add': add,      'subtract': subtract,      'multiply': multiply  }    def main():      # 用户输入      while True:          try:              operation = input("请输入操作（add, subtract, multiply）: ").strip().lower()              if operation not in operations:                  print("无效的操作，请输入add, subtract, 或 multiply")                  continue                            # 获取两个数字作为输入              num1 = float(input("请输入第一个数字: "))              num2 = float(input("请输入第二个数字: "))                            # 调用相应的函数              result = operations[operation](num1, num2)              print(f"{operation.title()}的结果: {result}")                    except ValueError:              print("请输入有效的数字")    if __name__ == "__main__":      main()

def greet_english(name):      return f"Hello, {name}!"    def greet_spanish(name):      return f"Hola, {name}!"    def greet_french(name):      return f"Bonjour, {name}!"    # 创建一个字典来映射语言到对应的问候函数  greeting_functions = {      'english': greet_english,      'spanish': greet_spanish,      'french': greet_french  }    def main():      # 假设这是从用户输入、配置文件或其他来源获取的      language = 'spanish'      name = 'Alice'            # 检查语言是否在映射中      if language in greeting_functions:          # 使用映射来调用函数          greeting = greeting_functions[language](name)          print(greeting)      else:          print(f"Unsupported language: {language}")    if __name__ == "__main__":      main()

def add(x, y):      return x + y    def subtract(x, y):      return x - y    def multiply(x, y):      return x * y    # 将函数名映射到函数对象  operation_functions = {      'add': add,      'subtract': subtract,      'multiply': multiply  }    def call_operation(operation_name, x, y):      # 检查操作名是否在映射中      if operation_name in operation_functions:          # 从映射中检索函数并调用它          result = operation_functions[operation_name](x, y)          print(f"Result of {operation_name}: {result}")      else:          print(f"Unsupported operation: {operation_name}")    # 假设这是从用户输入或其他来源获取的  operation = 'add'  x = 5  y = 3    # 调用函数  call_operation(operation, x, y)