[3.8] bpo-36541: lib2to3: Support named assignment expressions (GH-12702) #19315
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There are two copies of the grammar -- the one used by Python itself as Grammar/Grammar, and the one used by lib2to3 which has necessarily diverged at Lib/lib2to3/Grammar.txt because it needs to support older syntax an we want it to be reasonable stable to avoid requiring fixer rewrites. This brings suport for syntax like `if x:= foo():` to match what the live Python grammar does. This should've been added at the time of the walrus operator itself, but lib2to3 being independent is often overlooked. So we do consider this a bugfix rather than enhancement. (cherry picked from commit 3c3aa45) Co-authored-by: Tim Hatch <tim@timhatch.com>
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There are two copies of the grammar -- the one used by Python itself as
Grammar/Grammar, and the one used by lib2to3 which has necessarily diverged at
Lib/lib2to3/Grammar.txt because it needs to support older syntax an we want it
to be reasonable stable to avoid requiring fixer rewrites.
This brings suport for syntax like
if x:= foo():to match what the livePython grammar does.
This should've been added at the time of the walrus operator itself, but lib2to3 being
independent is often overlooked. So we do consider this a bugfix rather than enhancement.
(cherry picked from commit 3c3aa45)
Co-authored-by: Tim Hatch tim@timhatch.com
https://bugs.python.org/issue36541
Automerge-Triggered-By: @gpshead