Allow hasattr() function

What’s wrong

WPS421 forbids calling some built-in functions, which includes hasattr().

How it should be

The function hasattr() should be allowed. There are certain scenarios where using hasattr() makes sense, and sometimes is even faster (as even outlined in the referenced video @ 13:34-14:15 mark)

For code readability, if hasattr(foo, 'bar'): is cleaner than if getattr(foo, 'bar', None):.

I believe there was an argument against using hasattr() in python2, but I don’t believe the same argument is valid for python3.

Flake8 version and plugins

n/a

pip information

n/a

OS information

n/a

[Dresdn]

These are good points. However, getattr outputs wow just like hasattr does. By that logic, getattr should be added to the FUNCTIONS_BLACKLIST as well then, yes?

To be clear, I don’t advocate blacklisting getattr as there are semantic and performance reasons for using it.

Semantically, I think that if hasattr(A, 'foo') is clearer than if getattr(A, 'foo', False), which was the reasoning behind opening this issue. Do you agree?

[rubancar]

what @Dresdn says makes sense, one more reason in favor of allow hasattr is that the logic behind this one is performed by calling getattr and catching AttributteError, so, at the end both funcions are base on the same logic, It does not make sense to allow getattr and and issue a warning on hasattr