create_function什么意思

`create_function`是一个在Python中用于动态创建函数的关键字，它主要用于Python的内置模块`functools`或者`ast`模块。这两个模块提供了创建匿名函数（lambda函数）的能力，它们允许你在运行时生成函数对象，而不是先编写好函数定义再调用。

例如，`functools`中的`lru_cache`装饰器就经常配合`create_function`来创建缓存的函数。下面是一个简单的例子：

from functools import create_function

# 动态创建一个加法函数
add = create_function(lambda x, y: x + y)
print(add(2, 3))  # 输出：5

而`ast`模块则更常用于解析和生成抽象语法树，可以用来构建更复杂的函数表达式。但是请注意，Python 3.6及更高版本已经引入了`functools.partial`和更简洁的语法，因此在新版本的Python中直接使用lambda表达式更为常见，`create_function`的功能可能不再推荐使用。

相关问题

oracle create function syntax

The syntax for creating a function in Oracle is:

CREATE [OR REPLACE] FUNCTION function_name
    [(parameter_name [IN | OUT | IN OUT] data_type [, ...])]
RETURN return_data_type
IS
    [declaration_section]
BEGIN
    executable_section
    [EXCEPTION
        exception_section]
END [function_name];

Here is a brief explanation of each section:

- `CREATE [OR REPLACE] FUNCTION`: This is the SQL statement used to create a function. The `OR REPLACE` option allows you to modify an existing function instead of creating a new one.
- `function_name`: This is the name of the function you want to create.
- `parameter_name`: These are the input parameters for the function.
- `data_type`: This is the data type of the input parameters.
- `return_data_type`: This is the data type of the value returned by the function.
- `declaration_section`: This is an optional section where you can declare variables and constants used in the function.
- `executable_section`: This is the section where you write the code that executes when the function is called.
- `EXCEPTION`: This is an optional section where you can handle exceptions that occur in the function.
- `exception_section`: This is the section where you write the code to handle exceptions.

Note that the `IS` keyword separates the parameter and declaration sections from the executable section. The `END` keyword followed by the function name terminates the function definition.