Y066 cases that can't be rewritten

[tusharsadhwani]

Consider this case:

import sys

if sys.version_info < (3, 8):  # Y066 use "if sys.version_info >= (3, 8)"
    def bar(x): ...
elif sys.version_info >= (3, 10):
    def bar(x, *, bar=True): ...
else:
    def bar(x, *, bar=True, baz=False): ...

I don't think it is possible to rewrite this code with if sys.version_info >= (3, 8). Should Y066 be raised in this case?

[tusharsadhwani]

Specifically, Y066's suggestions are only applicable if Y066 is raised on every if and elif condition in the chain.

[AlexWaygood]

Can't your example be rewritten to

if sys.version_info >= (3, 10):
    def bar(x, *, bar=True): ...
elif sys.version_info >= (3, 8):
    def bar(x, *, bar=True, baz=False): ...
else:
    def bar(x): ...

?

[tusharsadhwani]

My bad! You're right, the else clause is equivalent to >= 3.8.

[tusharsadhwani]

It does get a bit dicey in some cases, like:

if sys.version_info < (3, 8):  # Y066 use "if sys.version_info >= (3, 8)"
    def bar(x): ...
elif sys.version_info == (3, 10):
    def bar(x, *, bar=True): ...
else:
    def bar(x, *, bar=True, baz=False): ...

is not equivalent to:

if sys.version_info == (3, 10):
    def bar(x, *, bar=True): ...
elif sys.version_info >= (3, 8):
    def bar(x, *, bar=True, baz=False): ...
else:
    def bar(x): ...

For Python 3.11, it will execute the wrong block, but it's hard to argue about that one.

[AlexWaygood]

I think we have another rule that warns against == comparisons with sys.version_info, because sys.version_info is always a tuple longer than 2 elements, so sys.version_info == (3, 10) will always resolve to False