wehub-resource-sync
52 lines
1.7 KiB
Python
52 lines
1.7 KiB
Python
"""Utility to lazy load modules."""
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import importlib
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import sys
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import types
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class LazyLoader(types.ModuleType):
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"""Class for module lazy loading.
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This class helps lazily load modules at package level, which avoids pulling in large
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dependencies like `tensorflow` or `torch`. This class is mirrored from wandb's LazyLoader:
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https://github.com/wandb/wandb/blob/79b2d4b73e3a9e4488e503c3131ff74d151df689/wandb/sdk/lib/lazyloader.py#L9
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"""
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def __init__(self, local_name, parent_module_globals, name):
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self._local_name = local_name
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self._parent_module_globals = parent_module_globals
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self._module = None
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super().__init__(str(name))
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def _load(self):
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"""Load the module and insert it into the parent's globals."""
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if self._module:
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# If already loaded, return the loaded module.
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return self._module
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# Import the target module and insert it into the parent's namespace
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module = importlib.import_module(self.__name__)
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self._parent_module_globals[self._local_name] = module
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sys.modules[self._local_name] = module
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# Update this object's dict so that if someone keeps a reference to the `LazyLoader`,
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# lookups are efficient (`__getattr__` is only called on lookups that fail).
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self.__dict__.update(module.__dict__)
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return module
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def __getattr__(self, item):
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module = self._load()
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return getattr(module, item)
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def __dir__(self):
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module = self._load()
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return dir(module)
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def __repr__(self):
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if not self._module:
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return f"<module '{self.__name__} (Not loaded yet)'>"
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return repr(self._module)
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