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activestate recipe for code to source and back fails on 3.3+, core Python bug?

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The recipe in question is here 
http://code.activestate.com/recipes/578353-code-to-source-and-back. 
I've called it c2sab in the test code below.

The problem is that the class name gets dropped during the round trip, 
but only if a list, dict or set comprehension or a generator expression 
is involved, and only from the code.co_consts tuple.  Hopefully the code 
and output that follows makes sense.

<code>
import c2sab
import inspect

class Comps():

     def listcomp(self):
         self.lc = [x for x in range(10)]

     def genexpr(self):
         self.ge = (x for x in range(10))

     def dictcomp(self):
         self.dc = {x: x**2 for x in range(10)}

     def setcomp(self):
         self.sc = {x for x in range(10)}

methods = inspect.getmembers(Comps, inspect.isfunction)
for _, method in methods:
     print('Processing', method.__name__)
     code = method.__code__
     recode = c2sab.recompile(*c2sab.uncompile(code))
     for offset, co_consts in enumerate(zip(code.co_consts, 
recode.co_consts)):
         old = co_consts[0]
         new = co_consts[1]
         if old != new:
             print('offset {} code |{}| not equal to recode 
|{}|'.format(offset, old, new))
     print()
</code>

<output>
Processing dictcomp
offset 2 code |Comps.dictcomp.<locals>.<dictcomp>| not equal to recode 
|dictcomp.<locals>.<dictcomp>|

Processing genexpr
offset 2 code |Comps.genexpr.<locals>.<genexpr>| not equal to recode 
|genexpr.<locals>.<genexpr>|

Processing listcomp
offset 2 code |Comps.listcomp.<locals>.<listcomp>| not equal to recode 
|listcomp.<locals>.<listcomp>|

Processing setcomp
offset 2 code |Comps.setcomp.<locals>.<setcomp>| not equal to recode 
|setcomp.<locals>.<setcomp>|
</output>

I can reproduce the above on 3.3 to 3.6 inclusive on Windows 10.  This 
has no impact on 3.2 or lower as the field in question is new in 
co_consts for 3.3.

So is my analysis correct?  If yes I'll be reporting a bug although I've 
no idea what against, if no what have I overlooked?

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence

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activestate recipe for code to source and back fails on 3.3+, core Python bug? Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-12-01 18:57 +0000

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