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[Python-ideas] LOAD_NAME/LOAD_GLOBAL should be use getattr()

Serhiy Storchaka storchaka at gmail.com
Thu Sep 14 10:08:13 EDT 2017 
13.09.17 23:07, Lucas Wiman пише:
> On Wed, Sep 13, 2017 at 11:55 AM, Serhiy Storchaka 
> <storchaka at gmail.com 
> <mailto:storchaka at gmail.com>> wrote:
> 
>     [...] Calling __getattr__() will slow down the access to builtins.
>     And there is a recursion problem if module's __getattr__() uses
>     builtins.
> 
> 
>   The first point is totally valid, but the recursion problem doesn't 
> seem like a strong argument. There are already lots of recursion 
> problems when defining custom __getattr__ or __getattribute__ methods, 
> but on balance they're a very useful part of the language.

In normal classes we have the recursion problem in __getattr__() only 
with accessing instance attributes. Builtins (like isinstance, getattr, 
AttributeError) can be used without problems. In module's __getattr__() 
all this is a problem.

Module attribute access can be implicit. For example comparing a string 
with a byte object in __getattr__() can trigger the lookup of 
__warningregistry__ and the infinity recursion.
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