Lỗi SyntaxError: Non-ASCII character ‘\xe1’ in file

[Dang_Ba_Kiet_Nguyen (đăng Bá Kiệt Nguyễn)]

SyntaxError: Non-ASCII character ‘\xe1’ in file .\ex2.py on line 1, but no encoding declared; see http://python.org/dev/
peps/pep-0263/ for details

[SITUVN.gcd]

Khai báo ở đầu tập tin:

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