TypeError Python Class

Question

我有一个库（caffe），它有以下定义：

class NetSpec(object):
    def __init__(self):
        super(NetSpec, self).__setattr__('tops', OrderedDict())
    def __setattr__(self, name, value):
        self.tops[name] = value
    def __getattr__(self, name):
        return self.tops[name]
    def to_proto(self):
        names = {v: k for k, v in self.tops.iteritems()}
        autonames = {}
        layers = OrderedDict()
        for name, top in self.tops.iteritems():
            top.fn._to_proto(layers, names, autonames)
        net = caffe_pb2.NetParameter()
        net.layer.extend(layers.values())
        return net

当我尝试使用 n = caffe.NetSpec() 调用它时，出现以下错误：

  File "../../python/caffe/layers.py", line 84, in __init__
    super(NetSpec, self).__setattr__('tops', OrderedDict())
TypeError: must be type, not None

我检查了SO-9698614，SO-576169和SO-489269，但它们没有导致解决方案。 我的类是一个新型类，我不明白为什么它不起作用。

完整跟踪：

Traceback (most recent call last):
  File "<ipython-input-72-694741de221d>", line 1, in <module>
    runfile('/home/shaunak/caffe-pr2086/examples/wine/classify.py', wdir='/home/shaunak/caffe-pr2086/examples/wine')
  File "/home/shaunak/anaconda/lib/python2.7/site-packages/spyderlib/widgets/externalshell/sitecustomize.py", line 682, in runfile
    execfile(filename, namespace)
  File "/home/shaunak/anaconda/lib/python2.7/site-packages/spyderlib/widgets/externalshell/sitecustomize.py", line 78, in execfile
    builtins.execfile(filename, *where)
  File "/home/shaunak/caffe-pr2086/examples/wine/classify.py", line 26, in <module>
    f.write(str(logreg('examples/hdf5_classification/data/train.txt', 10)))
  File "/home/shaunak/caffe-pr2086/examples/wine/classify.py", line 18, in logreg
    n = caffe.NetSpec()
  File "../../python/caffe/layers.py", line 84, in __init__
    super(NetSpec, self).__setattr__('tops', OrderedDict())
TypeError: must be type, not None

Answer 1

不知何故，您设法将NetSpec绑定到某处None：

>>> super(None, object())
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: must be type, not None

该错误指示NetSpec全局绑定到 None 。

您还可以通过直接转到实例__dict__属性来绕过 NetSpec.__setattr__ 方法：

class NetSpec(object):
    def __init__(self):
       self.__dict__['tops'] = OrderedDict()

从您共享的代码来看，这可能是罪魁祸首：

from .layers import layers, params, NetSpec

这将导入caffe.layers但caffe.layers重新绑定到Layers()实例。然后，这可能会触发 Python 再次删除该模块，因为还没有对它的其他引用（取决于创建sys.modules引用的时间和方式），从而导致所有全局变量重新绑定到 None（包括 NetSpec ）。