You should use something like:
#!/usr/bin/python
# -*- coding: utf-16be -*-
on first or second line (the important bit is coding
, :
or =
(so other answer are ok, if you put on top) and the codec. See PEP 263 for the syntax.
You should check that you do not have BOM at beginning (BOM is allowed on generic UTF-16, but not when the endianess is specified). Editors get it often wrong.
But in general I would recommend to use UTF-8 as encoding for code: it is much better supported by editors, and it is the default for Python3. Both UTF-8 and UTF-16 are just encoding of Unicode, so the support should be the same. Note: really Python2 will use UTF16 like encoding internally (UCS2), Python3 dynamically (per string) select UFT-8, UTF-16 or UTF-32. but forget about internal, this is a question of editor.
Note: The source encoding do no matter for executing (run time) the code. The default encoding to read and write files and to stdout are independent of code, they just depend on OS and environment.