En Mon, 24 Nov 2008 02:11:49 -0200, Rafe <[EMAIL PROTECTED]> escribió:
What are the pros and cons of these two patterns (and are there any
other)? Which is the best way to dynamically get an attribute from a
module from within the same module?
1) Using the name of the module
this_module = sys.modules[__name__]
attr = getattr(this_module, "whatever", None)
2) using globals
globals()["whatever"]
3) using the bare name:
whatever
1) and 2) are useful when the desired name is variable, not a constant
like "whatever".
I have been using #1 for two reasons. First, I will never run this
module directly, so __name__ will always be the module name and not
"__main__".
(note that it works even with __main__)
Second, I can use this in a class to decide whether I want
the module where the class came from or, if I make the class a base
for a class in another module, the module where the sub-class is.
I don't completely understand your use case. In the expression:
getattr(some_module, attribute_name)
you may use any module as the first argument (the current module, or any
other).
I am not familiar with the scope, pros or cons of globals() so I would
love to hear comments on this subject.
Perhaps if you explain in more detail your use case, somebody else may
have further comments...
I don't have the need to use globals()[name] very often.
--
Gabriel Genellina
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