12.09.17 19:17, Neil Schemenauer пише:
This is my idea of making module properties work. It is necessary
for various lazy-loading module ideas and it cleans up the language
IMHO. I think it may be possible to do it with minimal backwards
compatibility problems and performance regression.
To me, the main issue with module properties (or module __getattr__)
is that you introduce another level of indirection on global
variable access. Anywhere the module.__dict__ is used as the
globals for code execution, changing LOAD_NAME/LOAD_GLOBAL to have
another level of indirection is necessary. That seems inescapable.
Introducing another special feature of modules to make this work is
not the solution, IMHO. We should make module namespaces be more
like instance namespaces. We already have a mechanism and it is
getattr on objects.
There is a difference between module namespaces and instance namespaces.
LOAD_NAME/LOAD_GLOBAL fall back to builtins if the name is not found in
the globals dictionary. Calling __getattr__() will slow down the access
to builtins. And there is a recursion problem if module's __getattr__()
uses builtins.
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