这似乎是一个答案的开始。 我需要从Python 3.2的inspect.getattr_static中回溯一些项目,以使其正常工作,以便它不会调用只会生成新对象的属性。 这是我想出来的代码:
import types
class TreeYielder(object):
def __init__(self, yieldValue = None):
'''
`yieldValue` should be a lambda function that
returns True/False or a function/method call that
will be passed the value of a current attribute
'''
self.currentStack = []
self.yieldValue = yieldValue
self.stackVals = []
t = types
self.nonIterables = [t.IntType, t.StringType, t.UnicodeType, t.LongType,
t.FloatType, t.NoneType, t.BooleanType]
def run(self, obj, memo = None):
'''
traverse all attributes of an object looking
for subObjects that meet a certain criteria.
yield them.
`memo` is a dictionary to keep track of objects
that have already been seen
The original object is added to the memo and
also checked for yieldValue
'''
if memo is None:
memo = {}
self.memo = memo
if id(obj) in self.memo:
self.memo[id(obj)] += 1
return
else:
self.memo[id(obj)] = 1
if self.yieldValue(obj) is True:
yield obj
self.currentStack.append(obj)
tObj = type(obj)
if tObj in self.nonIterables:
pass
elif tObj == types.DictType:
for keyX in obj:
dictTuple = ('dict', keyX)
self.stackVals.append(dictTuple)
x = obj[keyX]
for z in self.run(x, memo=memo):
yield z
self.stackVals.pop()
elif tObj in [types.ListType, types.TupleType]:
for i,x in enumerate(obj):
listTuple = ('listLike', i)
self.stackVals.append(listTuple)
for z in self.run(x, memo=memo):
yield z
self.stackVals.pop()
else:
try:
instance_dict = object.__getattribute__(obj, "__dict__")
except AttributeError:
return
for x in instance_dict:
try:
gotValue = object.__getattribute__(obj, x)
except:
continue
objTuple = ('getattr', x)
self.stackVals.append(objTuple)
try:
for z in self.run(gotValue, memo=memo):
yield z
except RuntimeError:
raise Exception("Maximum recursion on:\n%s" % self.currentLevel())
self.stackVals.pop()
self.currentStack.pop()
def currentLevel(self):
currentStr = ""
for stackType, stackValue in self.stackVals:
if stackType == 'dict':
if isinstance(stackValue, str):
currentStr += "['" + stackValue + "']"
elif isinstance(stackValue, unicode):
currentStr += "[u'" + stackValue + "']"
else:
currentStr += "[" + str(stackValue) + "]"
elif stackType == 'listLike':
currentStr += "[" + str(stackValue) + "]"
elif stackType == 'getattr':
currentStr += ".__getattribute__('" + stackValue + "')"
else:
raise Exception("Cannot get attribute of type %s" % stackType)
return currentStr
这段代码可以让你运行类似这样的内容:
class Mock(object):
def __init__(self, mockThing, embedMock = True):
self.abby = 30
self.mocker = mockThing
self.mockList = [mockThing, mockThing, 40]
self.embeddedMock = None
if embedMock is True:
self.embeddedMock = Mock(mockThing, embedMock = False)
mockType = lambda x: x.__class__.__name__ == 'Mock'
subList = [100, 60, -2]
myList = [5, 20, [5, 12, 17], 30, {'hello': 10, 'goodbye': 22, 'mock': Mock(subList)}, -20, Mock(subList)]
myList.append(myList)
ty = TreeYielder(mockType)
for val in ty.run(myList):
print(val, ty.currentLevel())
并获得:
(<__main__.Mock object at 0x01DEBD10>, "[4]['mock']")
(<__main__.Mock object at 0x01DEF370>, "[4]['mock'].__getattribute__('embeddedMock')")
(<__main__.Mock object at 0x01DEF390>, '[6]')
(<__main__.Mock object at 0x01DEF3B0>, "[6].__getattribute__('embeddedMock')")
或者运行:
high = lambda x: isinstance(x, (int, float)) and x > 10
ty = TreeYielder(high)
for val in ty.run(myList):
print(val, ty.currentLevel())
并获得:
(20, '[1]')
(12, '[2][1]')
(17, '[2][2]')
(30, '[3]')
(22, "[4]['goodbye']")
(100, "[4]['mock'].__getattribute__('embeddedMock').__getattribute__('mocker')[0]")
(60, "[4]['mock'].__getattribute__('embeddedMock').__getattribute__('mocker')[1]")
(40, "[4]['mock'].__getattribute__('embeddedMock').__getattribute__('mockList')[2]")
我仍在努力弄清楚为什么找不到.abby文件,但我认为即使在这个阶段发布也是值得的,因为它比我开始时更接近正确的方向。
pickle.Pickler
类吗?源代码包含在.../Lib/pickle.py
中。这样做应该允许您重用大量代码并捕获PickleError
以执行您所描述的操作 - 同时利用Python已经建立的成熟的pickling协议。 - martineau