python file

# -*- coding: utf-8 -*-

print 'original python file'

fix_print.py

class FixPrint(fixer_base.BaseFix):

    BM_compatible = True

    PATTERN = """
              simple_stmt< any* bare='print' any* > | print_stmt
              """

    def transform(self, node, results):
        assert results
        bare_print = results.get("bare")

when i use 2to3/lib2to3/fix_print.py to transform the python file.

if i print the node,it shows

# -*- coding: utf-8 -*-

print 'original python file'

why does the node include the annotation “# –– coding: utf-8 –-“

Thank you very much if you can explain this.