Enhancing `getattr` to support nested attribute access with dotted strings

[danielkonecny (Daniel Konečný)]

@Rosuav

There’s really no reason to have getattr with a keyword argument; the exact same effect can be had with a brand new function.

I have no preference in how this is exposed in Python, I just wanted to express my interest in having such functionality implemented natively.

@Rosuav

Have you tested this? First find out whether hasattr is actually materially slower than checking for the exception. Keep in mind that it may very well be using exception handling internally, which would remove a lot of the difference; and what difference remains is likely to be on the order of nanoseconds per lookup. Find out whether it makes enough difference to make a difference.

You are right, sorry for my confusion. Citing from docs of hasattr:

This is implemented by calling getattr(object, name) and seeing whether it raises an AttributeError or not.

I expect no more-performant yet consistent implementation can be made. But still, if it was worth it to have hasattr implemented as a built-in function, a nested variant would make sense just out of pure consistency (if such getattr is implemented). Even if it was a simple try/except block with returns of booleans.