You are much better off using getattr()
instead of going directly to the __dict__
structure.
Not because it's faster or slower, but because the official API works in all circumstances, including for classes that do not have a __dict__
(when using __slots__
for example), or when an object implements the __getattr__
or __getattribute__
hooks, or when the attribute in question is a descriptor (such as a property
), or a class attribute.
If you want to know if any one python statement or technique is faster than another, use the timeit
module to measure the difference:
>>> import timeit
>>> class Foo(object):
... pass
...
>>> foo = Foo()
>>> foo.bar = 'spam'
>>> timeit.timeit("getattr(foo, 'bar')", 'from __main__ import foo')
0.2125859260559082
>>> timeit.timeit("foo.__dict__['bar']", 'from __main__ import foo')
0.1328279972076416
You can see that directly accessing __dict__
is faster, but getattr()
does a lot more work.
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