Python 中的适应性描述符
Adaptable descriptor in Python
我想在 class 上创建某种描述符 returns 代理对象。代理对象在索引时检索对象的成员并将索引应用于它们。然后它returns总和。
例如,
class NDArrayProxy:
def __array__(self, dtype=None):
retval = self[:]
if dtype is not None:
return retval.astype(dtype, copy=False)
return retval
class ArraySumProxy(NDArrayProxy):
def __init__(self, arrays):
self.arrays = arrays
@property
def shape(self):
return self.arrays[0].shape
def __getitem__(self, indices):
return np.sum([a[indices]
for a in self.arrays],
axis=0)
当我将实际数组作为成员变量时,此解决方案运行良好:
class CompartmentCluster(Cluster):
"""
Base class for cluster that manages evidence.
"""
def __init__(self, **kwargs):
super().__init__(**kwargs)
self.variable_evidence = ArraySumProxy([])
class BasicEvidenceTargetCluster(CompartmentCluster):
# This class variable creates a Python object named basic_in on the
# class, which implements the descriptor protocol.
def __init__(self,
*,
**kwargs):
super().__init__(**kwargs)
self.basic_in = np.zeros(self.size)
self.variable_evidence.arrays.append(self.basic_in)
class ExplanationTargetCluster(CompartmentCluster):
"""
These clusters accept explanation evidence.
"""
def __init__(self, **kwargs):
super().__init__(**kwargs)
self.explanation_in = np.zeros(self.size)
self.variable_evidence.arrays.append(self.explanation_in)
class X(BasicEvidenceTargetCluster, ExplanationTargetCluster):
pass
现在我已经将我的数组更改为 Python 描述符(cluster_signal
实现了返回 numpy 数组的描述符协议):
class CompartmentCluster(Cluster):
"""
Base class for cluster that manages evidence.
"""
def __init__(self, **kwargs):
super().__init__(**kwargs)
self.variable_evidence = ArraySumProxy([])
class BasicEvidenceTargetCluster(CompartmentCluster):
# This class variable creates a Python object named basic_in on the
# class, which implements the descriptor protocol.
basic_in = cluster_signal(text="Basic (in)",
color='bright orange')
def __init__(self,
*,
**kwargs):
super().__init__(**kwargs)
self.variable_evidence.arrays.append(self.basic_in)
class ExplanationTargetCluster(CompartmentCluster):
"""
These clusters accept explanation evidence.
"""
explanation_in = cluster_signal(text="Explanation (in)",
color='bright yellow')
def __init__(self, **kwargs):
super().__init__(**kwargs)
self.variable_evidence.arrays.append(self.explanation_in)
class X(BasicEvidenceTargetCluster, ExplanationTargetCluster):
pass
这不起作用,因为追加语句追加了描述符调用的结果。我需要的是附加一个绑定方法或类似的代理。修改我的解决方案的最佳方式是什么?简而言之:变量 basic_in
和 explanation_in
是 numpy
数组。他们现在是描述符。我想开发一些使用描述符而不是需要实际数组的 ArraySumProxy
版本。
当您访问一个描述符时,它会被求值,您只能得到值。由于您的描述符并不总是 return 相同的对象(我猜您无法避免它?),因此您不想在初始化代理时访问描述符。
避免访问它的最简单方法是只记住它的名称,而不是:
self.variable_evidence.arrays.append(self.basic_in)
你做到了:
self.variable_evidence.arrays.append((self, 'basic_in'))
然后,当然,variable_evidence
必须意识到这一点并执行 getattr(obj, name)
才能访问它。
另一种选择是使描述符 return 成为稍后评估的代理对象。我不知道你在做什么,但这可能是太多的代理人不合口味...
编辑
或者...您可以存储 getter:
self.variable_evidence.arrays.append(lambda: self.basic_in)
我想在 class 上创建某种描述符 returns 代理对象。代理对象在索引时检索对象的成员并将索引应用于它们。然后它returns总和。
例如,
class NDArrayProxy:
def __array__(self, dtype=None):
retval = self[:]
if dtype is not None:
return retval.astype(dtype, copy=False)
return retval
class ArraySumProxy(NDArrayProxy):
def __init__(self, arrays):
self.arrays = arrays
@property
def shape(self):
return self.arrays[0].shape
def __getitem__(self, indices):
return np.sum([a[indices]
for a in self.arrays],
axis=0)
当我将实际数组作为成员变量时,此解决方案运行良好:
class CompartmentCluster(Cluster):
"""
Base class for cluster that manages evidence.
"""
def __init__(self, **kwargs):
super().__init__(**kwargs)
self.variable_evidence = ArraySumProxy([])
class BasicEvidenceTargetCluster(CompartmentCluster):
# This class variable creates a Python object named basic_in on the
# class, which implements the descriptor protocol.
def __init__(self,
*,
**kwargs):
super().__init__(**kwargs)
self.basic_in = np.zeros(self.size)
self.variable_evidence.arrays.append(self.basic_in)
class ExplanationTargetCluster(CompartmentCluster):
"""
These clusters accept explanation evidence.
"""
def __init__(self, **kwargs):
super().__init__(**kwargs)
self.explanation_in = np.zeros(self.size)
self.variable_evidence.arrays.append(self.explanation_in)
class X(BasicEvidenceTargetCluster, ExplanationTargetCluster):
pass
现在我已经将我的数组更改为 Python 描述符(cluster_signal
实现了返回 numpy 数组的描述符协议):
class CompartmentCluster(Cluster):
"""
Base class for cluster that manages evidence.
"""
def __init__(self, **kwargs):
super().__init__(**kwargs)
self.variable_evidence = ArraySumProxy([])
class BasicEvidenceTargetCluster(CompartmentCluster):
# This class variable creates a Python object named basic_in on the
# class, which implements the descriptor protocol.
basic_in = cluster_signal(text="Basic (in)",
color='bright orange')
def __init__(self,
*,
**kwargs):
super().__init__(**kwargs)
self.variable_evidence.arrays.append(self.basic_in)
class ExplanationTargetCluster(CompartmentCluster):
"""
These clusters accept explanation evidence.
"""
explanation_in = cluster_signal(text="Explanation (in)",
color='bright yellow')
def __init__(self, **kwargs):
super().__init__(**kwargs)
self.variable_evidence.arrays.append(self.explanation_in)
class X(BasicEvidenceTargetCluster, ExplanationTargetCluster):
pass
这不起作用,因为追加语句追加了描述符调用的结果。我需要的是附加一个绑定方法或类似的代理。修改我的解决方案的最佳方式是什么?简而言之:变量 basic_in
和 explanation_in
是 numpy
数组。他们现在是描述符。我想开发一些使用描述符而不是需要实际数组的 ArraySumProxy
版本。
当您访问一个描述符时,它会被求值,您只能得到值。由于您的描述符并不总是 return 相同的对象(我猜您无法避免它?),因此您不想在初始化代理时访问描述符。
避免访问它的最简单方法是只记住它的名称,而不是:
self.variable_evidence.arrays.append(self.basic_in)
你做到了:
self.variable_evidence.arrays.append((self, 'basic_in'))
然后,当然,variable_evidence
必须意识到这一点并执行 getattr(obj, name)
才能访问它。
另一种选择是使描述符 return 成为稍后评估的代理对象。我不知道你在做什么,但这可能是太多的代理人不合口味...
编辑
或者...您可以存储 getter:
self.variable_evidence.arrays.append(lambda: self.basic_in)