Add support for py3.

lesscpy/lessc/lexer.py

@@ -11,6 +11,7 @@
 """
 import re
 import ply.lex as lex
+from six import string_types
 
 from lesscpy.lib import dom
 from lesscpy.lib import css
@@ -465,7 +466,7 @@ class LessLexer:
         Load lexer with content from `file` which can be a path or a file
         like object.
         """
-        if isinstance(file, basestring):
+        if isinstance(file, string_types):
             with open(file) as f:
                 self.lexer.input(f.read())
         else:

requirements.txt

@@ -1 +1,2 @@
 ply
+six