我有很多類,有這樣的代碼.每個(gè)__init__都會(huì)啟動(dòng)一個(gè)線程和一個(gè)帶有該類名稱的記錄器.如何在__init__中以字符串形式獲取當(dāng)前類的名稱？請(qǐng)注意,self可能不是當(dāng)前類的實(shí)例,因此以下內(nèi)容并非萬(wàn)無(wú)一失.

from threading import Thread
import logging

def myClassName(myclass):
    myclass._class_name = myclass.__name__
    return myclass

@myClassName
class SomeClass(object):
    def __init__(self):
        class_name = type(self)._class_name
        print "My class name in __init__ is", class_name
        self.thread = Thread(name=class_name)
        self.logger = logging.getLogger(class_name)

更新：

澄清：

>我想要定義類的名稱,而不是類的名稱
傳入的對(duì)象.
>我不想硬編碼類的名稱.
>我希望能夠輕松地將示例從一個(gè)腳本復(fù)制/粘貼到
另一個(gè),并且對(duì)獨(dú)特類名的提及越少越好.
(繼承不是很有效,因?yàn)橛凶銐虻淖远x
差異讓它變得尷尬.但不小心留下了名字
錯(cuò)誤的類是一個(gè)難以找到的bug.)

解決方法:

在Python 3中,這非常簡(jiǎn)單,我們可以使用__class__單元變量來(lái)獲取當(dāng)前類.

在Python 2中,我們可以通過(guò)使用元類在函數(shù)globals范圍中注入類的名稱并稍后清理它來(lái)實(shí)現(xiàn)類似的功能.

from functools import wraps
from types import FunctionType


def decorate(func, class_name):
    @wraps(func)
    def wrapper(*args, **kwargs):
        sentinel = object()
        actual_value = func.__globals__.get('__class__', sentinel)
        func.__globals__['__class__'] = class_name
        try:
            result = func(*args, **kwargs)
        finally:
            if actual_value is sentinel:
                del func.__globals__['__class__']
            else:
                func.__globals__['__class__'] = actual_value
        return result
    return wrapper


class Meta(type):
    def __new__(cls, name, bases, attrs):
        for k, v in attrs.items():
            if isinstance(v, FunctionType):
                attrs[k] = decorate(v, name)
        return type.__new__(cls, name, bases, attrs)


class A:
    __metaclass__ = Meta
    def func(self):
        print(__class__)
        print('Inside A')


class B(A):
    def func(self):
        print(__class__)
        print('Inside B')
        super(B, self).func()


B().func()

輸出：

B
Inside B
A
Inside A

要將__class__變量作為類對(duì)象本身,我們可以進(jìn)行一些更改：

def decorate(func, cls):
    @wraps(func)
    def wrapper(*args, **kwargs):
        sentinel = object()
        actual_value = func.__globals__.get('__class__', sentinel)
        func.__globals__['__class__'] = cls
        try:
            result = func(*args, **kwargs)
        finally:
            if actual_value is sentinel:
                del func.__globals__['__class__']
            else:
                func.__globals__['__class__'] = actual_value
        return result
    return wrapper


class Meta(type):
    def __new__(cls, name, bases, attrs):
        cls = type.__new__(cls, name, bases, attrs)
        for k, v in attrs.items():
            if isinstance(v, FunctionType):
                setattr(cls, k, decorate(v, cls))
        return cls

現(xiàn)在輸出將是：

<class '__main__.B'>
Inside B
<class '__main__.A'>
Inside A