Space before method brackets for built-in functions

[loechel]

I have the problem that black does a reformat of built-in functions, in my case on exec and eval as those have been statements in Python 2 but are methods in Python 3.

-        return exec("code", {}, {})
+        return exec ("code", {}, {})

Operating system: MacOS
Python version: 3.6.4
Black version: black, version 18.3a3
Does also happen on master: Yes

[ambv]

Yes, this is indeed a bug stemming from usage of lib2to3. We should probably just don't allow for the old exec and eval forms.