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nanjekyejoannah merged 3 commits into from
Jul 13, 2020
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bpo-32192: A basic lazy importer example #21330

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Add example on lazy imports
nanjekyejoannah Jul 5, 2020
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Use four spaces for indentation
nanjekyejoannah Jul 7, 2020
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nanjekyejoannah Jul 7, 2020
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21 changes: 21 additions & 0 deletions Doc/library/importlib.rst
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Expand Up @@ -1719,6 +1719,27 @@ To import a Python source file directly, use the following recipe
spec.loader.exec_module(module)


Implementing lazy imports
'''''''''''''''''''''''''

The example below shows how to implement lazy imports::
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import sys
import importlib.util
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def lazy_import(name):
spec = importlib.util.find_spec(name)
loader = importlib.util.LazyLoader(spec.loader)
spec.loader = loader
module = importlib.util.module_from_spec(spec)
sys.modules[name] = module
loader.exec_module(module)
return module

>>> lazy_typing = lazy_import("typing")
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>>> lazy_typing.TYPE_CHECKING
False



Setting up an importer
''''''''''''''''''''''
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