Question

提议的装饰器here能够继承方法的文档字符串，但不能继承属性和getter。

我试图天真地扩展它，但似乎属性的docstrings是只读的。有没有办法继承那些？

import types

def fix_docs(cls):
    for name, func in vars(cls).items():
        if isinstance(func, (types.FunctionType, property)) and not func.__doc__:
            print func, 'needs doc'
            for parent in cls.__bases__:
                parfunc = getattr(parent, name, None)
                if parfunc and getattr(parfunc, '__doc__', None):
                    func.__doc__ = parfunc.__doc__
                    break
    return cls


class X(object):
    """
    some doc
    """

    angle = 10
    """Not too steep."""

    def please_implement(self):
        """
        I have a very thorough documentation
        :return:
        """
        raise NotImplementedError

    @property
    def speed(self):
        """
        Current speed in knots/hour.
        :return:
        """
        return 0

    @speed.setter
    def speed(self, value):
        """

        :param value:
        :return:
        """
        pass

@fix_docs
class SpecialX(X):
    angle = 30

    def please_implement(self):
        return True

    @property
    def speed(self):
        return 10

    @speed.setter
    def speed(self, value):
        self.sp = value



help(X.speed)
help(X.angle)
help(SpecialX.speed)
help(SpecialX.ange)

这只能让我

Traceback (most recent call last):
<function please_implement at 0x036101B0> needs doc
<property object at 0x035BE930> needs doc
  File "C:\Program Files (x86)\JetBrains\PyCharm Community Edition 2016.2\helpers\pydev\pydevd.py", line 1556, in <module>
    globals = debugger.run(setup['file'], None, None, is_module)
  File "C:\Program Files (x86)\JetBrains\PyCharm Community Edition 2016.2\helpers\pydev\pydevd.py", line 940, in run
    pydev_imports.execfile(file, globals, locals)  # execute the script
  File "C:/Users/RedX/.PyCharm2016.2/config/scratches/scratch.py", line 48, in <module>
    class SpecialX(X):
  File "C:/Users/RedX/.PyCharm2016.2/config/scratches/scratch.py", line 10, in fix_docs
    func.__doc__ = parfunc.__doc__
TypeError: readonly attribute

Answer 1

是的，属性docstrings是只读的。你必须建立一个新的财产：

replacement = property(fget=original.fget,
                       fset=original.fset,
                       fdel=original.fdel,
                       __doc__=parentprop.__doc__)

并用原来替换原件。

替换原始函数的文档字符串然后重新生成属性以自动传递它可能稍微好一些：

original.fget.__doc__ = parentprop.__doc__
replacement = property(fget=original.fget,
                       fset=original.fset,
                       fdel=original.fdel)

Answer 2

此版本支持多重继承，并使用Expected behavior: (str "hello " "there") => "hello there" Actual behavior: (str "hello " "there") => "hello there"代替__mro__从基础文件复制文档。

__bases__

试验：

def fix_docs(cls):
    """
    This will copy all the missing documentation for methods from the parent classes.

    :param type cls: class to fix up.
    :return type: the fixed class.
    """
    for name, func in vars(cls).items():
        if isinstance(func, types.FunctionType) and not func.__doc__:
            for parent in cls.__bases__:
                parfunc = getattr(parent, name, None)
                if parfunc and getattr(parfunc, '__doc__', None):
                    func.__doc__ = parfunc.__doc__
                    break
        elif isinstance(func, property) and not func.fget.__doc__:
            for parent in cls.__bases__:
                parprop = getattr(parent, name, None)
                if parprop and getattr(parprop.fget, '__doc__', None):
                    newprop = property(fget=func.fget,
                                       fset=func.fset,
                                       fdel=func.fdel,
                                       parprop.fget.__doc__)
                    setattr(cls, name, newprop)
                    break

    return cls

继承属性getter文档

2 个答案: