据我了解，python模块永远不会导入两次，即该模块中的代码仅在首次导入时才执行。随后的import语句只需将模块添加到导入范围即可。

我有一个名为“ TiledConvC3D.py”的模块，但似乎已多次导入。我使用pdb在该模块的代码顶部打印堆栈。

这是从第一次执行模块开始的堆栈跟踪的结尾：

File "<anonymized>/python_modules/Theano/theano/gof/cmodule.py", line 328, in refresh
  key = cPickle.load(open(key_pkl, 'rb'))
File "<anonymized>/ops/TiledConvG3D.py", line 565, in <module>
  import TiledConvC3D
File "<anonymized>/ops/TiledConvC3D.py", line 18, in <module>
  pdb.traceback.print_stack()

它将继续执行多次。但是，第二次调用的完整堆栈跟踪不会显示对的任何调用reload，因此不应执行这些执行：

File "sup_train_conj_grad.py", line 103, in <module>
  dataset = Config.get_dataset(dataset_node)
File "<anonymized>/Config.py", line 279, in get_dataset
  from datasets import NewWiskott
File "<anonymized>/datasets/NewWiskott.py", line 16, in <module>
  normalizer_train = video.ContrastNormalizer3D(sigma, global_per_frame = False, input_is_5d = True)
File "<anonymized>/util/video.py", line 204, in __init__
  self.f = theano.function([input],output)
File "<anonymized>/python_modules/Theano/theano/compile/function.py", line 105, in function
  allow_input_downcast=allow_input_downcast)
File "<anonymized>/python_modules/Theano/theano/compile/pfunc.py", line 270, in pfunc
  accept_inplace=accept_inplace, name=name)
File "<anonymized>/python_modules/Theano/theano/compile/function_module.py", line 1105, in orig_function
  fn = Maker(inputs, outputs, mode, accept_inplace = accept_inplace).create(defaults)
File "/u/goodfeli/python_modules/Theano/theano/compile/function_module.py", line 982, in create
  _fn, _i, _o = self.linker.make_thunk(input_storage = input_storage_lists)
File "<anonymized>/python_modules/Theano/theano/gof/link.py", line 321, in make_thunk
  output_storage = output_storage)[:3]
File "<anonymized>/python_modules/Theano/theano/gof/cc.py", line 1178, in make_all
  output_storage = node_output_storage)
File "<anonymized>/python_modules/Theano/theano/gof/cc.py", line 774, in make_thunk
  cthunk, in_storage, out_storage, error_storage = self.__compile__(input_storage, output_storage)
File "<anonymized>/python_modules/Theano/theano/gof/cc.py", line 723, in __compile__
  output_storage)
File "<anonymized>/python_modules/Theano/theano/gof/cc.py", line 1037, in cthunk_factory
  module = get_module_cache().module_from_key(key=key, fn=self.compile_cmodule)
File "<anonymized>/python_modules/Theano/theano/gof/cc.py", line 59, in get_module_cache
  return cmodule.get_module_cache(config.compiledir)
File "<anonymized>/python_modules/Theano/theano/gof/cmodule.py", line 576, in get_module_cache
  _module_cache = ModuleCache(dirname, force_fresh=force_fresh)
File "<anonymized>/python_modules/Theano/theano/gof/cmodule.py", line 268, in __init__
  self.refresh()
File "<anonymized>/python_modules/Theano/theano/gof/cmodule.py", line 326, in refresh
  key = cPickle.load(open(key_pkl, 'rb'))
File "<anonymized>/ops/TiledConvV3D.py", line 504, in <module>
  import TiledConvG3D
File "<anonymized>/ops/TiledConvG3D.py", line 565, in <module>
  import TiledConvC3D
File "<anonymized>/ops/TiledConvC3D.py", line 22, in <module>
  pdb.traceback.print_stack()

此外，我还检查的ID
__builtin__.__import__。在主脚本的开头，我先导入__builtin__并打印，id(__builtin__.__import__)然后再进行其他任何导入。我还id(__builtin__.import__)从被多次导入的模块内部打印，并且id的值不变。

除了调用reload和override之外，还有其他机制__builtin__.__import__可以解释我的模块多次加载吗？