[New-bugs-announce] [issue43772] Minor repr error in typing.TypeVar.__ror__()

[Larry Hastings]

New submission from Larry Hastings <larry at hastings.org>:

The implementation of the | operator for TypeVar objects is as follows:

    def __or__(self, right):
        return Union[self, right]

    def __ror__(self, right):
        return Union[self, right]

I think the implementation of __ror__ is ever-so-slightly inaccurate.  Shouldn't it be this?

    def __ror__(self, left):
        return Union[left, self]

I assume this wouldn't affect runtime behavior, as unions are sets and are presumably unordered.  The only observable difference should be in the repr() (and only then if both are non-None), as this reverses the elements.  The repr for Union does preserve the order of the elements it contains, so it's visible to the user there.

----------
components: Library (Lib)
messages: 390524
nosy: larry
priority: low
severity: normal
stage: test needed
status: open
title: Minor repr error in typing.TypeVar.__ror__()
type: behavior
versions: Python 3.10

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Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue43772>
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