Marco Buttu added the comment:
The patch LGTM. I think there is just one type (see review).
By the way, looking at the PEP 0263, the sentence "To define a source code encoding, a magic comment must be placed into the source files either as first or second line in the file" actually is not true. Also because I did not see any point in the PEP that clarifies that the fist line has to be a comment. Maybe it could be deduced by the examples (all using the shebang), but maybe not, and the user could think this is a valid declaration:
print('très jolie') # -*- coding: ascii -*-
If you think is worth to clarify, I open an issue with a patch for the PEP 0263.