打字模块中的什么类型描述了一个类?什么类型描述了一个函数? [英] What type in the typing module describes a class? What type describes a function?

问题描述

Python 3.5 中新的 typing 模块提供了许多用于类型注释的工具.它是否提供了一个封装了类思想的对象或类型?功能的想法怎么样?

The new typing module in Python 3.5 provides a number of tools for use in type annotations. Does it provide an object or type that encapsulates the idea of class? How about the idea of function?

在以下定义装饰器的代码中，class_ 应该代表什么?function 应该代表什么?(typing.Callable 是不够的，因为例如一个类是可调用的，但代码试图识别方法.)( 中的 no_type_check() 装饰器Typing 模块本身可能是装饰器的原型，其行为类似.no_type_check() 本身没有任何注释、类型提示或其他.)

In the following code, which defines a decorator, what should stand in for class_? What should stand in for function? (typing.Callable is inadequate, because for example a class is callable, but the code is trying to identify methods.) (The no_type_check() decorator in the typing module itself might be a prototype for decorators that act like this. no_type_check() itself does not have any annotations, type-hint or otherwise.)

import typing

def is_double_underscore_name (name):
    return len(name) > 4 and name.startswith('__') and name.endswith('__')

# This code will not run, because 'class_' and 'function' are names that do not have any
# predefined meaning. See the text of the question.

# Note: This modifies classes in-place but (probably) does not modify functions in-place;
# this is not a considered design decision; it is just the easiest thing to do in a very
# basic example like this.
def do_something (class_or_function: typing.Union[class_, function]):
    if isinstance(class_or_function, class_):
        for name in class_or_function.__dict__:
            if not is_double_underscore_name(name):
                object = class_or_function.__dict__[name]
                if isinstance(object, function):
                    class_or_function.__dict__[name] = do_something(object)
        return class_or_function
    else:
        ... # return the function, modified in some way

推荐答案

类是 type 类型的实例.

函数属于 types.FunctionType 或 types.BuiltinFunctionType 类型.

Functions are of the types types.FunctionType or types.BuiltinFunctionType.

方法属于 types.MethodType 或 types.BuiltinMethodType 类型.

Methods are of the types types.MethodType or types.BuiltinMethodType.

types 已经成为 Python 的一部分......很长时间了.

types has been a part of Python for... a very long time.

这篇关于打字模块中的什么类型描述了一个类?什么类型描述了一个函数?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！