[issue26477] typing forward references and module attributes

[Martijn Pieters]

Martijn Pieters added the comment:

> I wonder why they forward references are evaluated *at all* at this point. 

The Union type tries to reduce the set of allowed types by removing any subclasses (so Union[int, bool] becomes Union[int] only). That's all fine, but it should not at that point fail if a forward reference is not available yet.

Arguably, the except NameError there should be converted to a except Exception, since forward references are supposed to be *a valid Python expression [...] and it should evaluate without errors once the module has been fully loaded.* (from the PEP); anything goes, and thus any error goes until the module is loaded.

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Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue26477>
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