[python] Working with UTF-8 encoding in Python source

Consider:

$ cat bla.py 
u = unicode('d…')
s = u.encode('utf-8')
print s
$ python bla.py 
  File "bla.py", line 1
SyntaxError: Non-ASCII character '\xe2' in file bla.py on line 1, but no encoding declared; see http://www.python.org/peps/pep-0263.html for details

How can I declare UTF-8 strings in source code?

Do not forget to verify if your text editor encodes properly your code in UTF-8.

Otherwise, you may have invisible characters that are not interpreted as UTF-8.

In the source header you can declare:

#!/usr/bin/env python
# -*- coding: utf-8 -*-
....

It is described in the PEP 0263:

Then you can use UTF-8 in strings:

#!/usr/bin/env python
# -*- coding: utf-8 -*-

u = 'idzie waz waska drózka'
uu = u.decode('utf8')
s = uu.encode('cp1250')
print(s)

This declaration is not needed in Python 3 as UTF-8 is the default source encoding (see PEP 3120).

In addition, it may be worth verifying that your text editor properly encodes your code in UTF-8. Otherwise, you may have invisible characters that are not interpreted as UTF-8.