Python 3 compatibility, at least with syntax and builtins.

Adds our very first dependency, on `six`.

11 files changed, 67 insertions, 55 deletions

diff --git a/scss/__init__.py b/scss/__init__.py
index 4a70fcf..6ba4b9d 100644
--- a/scss/__init__.py
+++ b/scss/__init__.py
@@ -36,6 +36,7 @@ xCSS:
 
 """
 from __future__ import absolute_import
+from __future__ import print_function
 
 from scss.scss_meta import BUILD_INFO, PROJECT, VERSION, REVISION, URL, AUTHOR, AUTHOR_EMAIL, LICENSE
 
@@ -54,6 +55,8 @@ import re
 import sys
 import textwrap
 
+import six
+
 from scss import config
 from scss.cssdefs import (
     SEPARATOR,
@@ -77,7 +80,7 @@ locate_blocks = None
 try:
     from scss._speedups import locate_blocks
 except ImportError:
-    print >>sys.stderr, "Scanning acceleration disabled (_speedups not found)!"
+    sys.stderr.write("Scanning acceleration disabled (_speedups not found)!\n")
     from scss._native import locate_blocks
 
 ################################################################################
@@ -322,12 +325,12 @@ class Scss(object):
         # defined globally to just searching the current directory
         self.search_paths = list(_default_search_paths)
         if self._search_paths is not None:
-            assert not isinstance(self._search_paths, basestring), \
+            assert not isinstance(self._search_paths, six.string_types), \
                 "`search_paths` should be an iterable, not a string"
             self.search_paths.extend(self._search_paths)
         else:
             if config.LOAD_PATHS:
-                if isinstance(config.LOAD_PATHS, basestring):
+                if isinstance(config.LOAD_PATHS, six.string_types):
                     # Back-compat: allow comma-delimited
                     self.search_paths.extend(config.LOAD_PATHS.split(','))
                 else:
@@ -725,7 +728,7 @@ class Scss(object):
             value = calculator.calculate(value)
             m_vars.set_variable(m_param, value)
         for p in m_params:
-            if p not in new_params and isinstance(m_vars.variable(p), basestring):
+            if p not in new_params and isinstance(m_vars.variable(p), six.string_types):
                 value = calculator.calculate(m_vars.variable(p))
                 m_vars.set_variable(p, value)
 
@@ -1022,7 +1025,7 @@ class Scss(object):
     #     first_val = None
     #     while True:
     #         val = self.calculator.calculate(block.argument, rule, rule.context, rule.options)
-    #         val = bool(False if not val or isinstance(val, basestring) and (val in ('0', 'false', 'undefined') or _variable_re.match(val)) else val)
+    #         val = bool(False if not val or isinstance(val, six.string_types) and (val in ('0', 'false', 'undefined') or _variable_re.match(val)) else val)
     #         if first_val is None:
     #             first_val = val
     #         if not val:
@@ -1093,7 +1096,7 @@ class Scss(object):
             _prop = calculator.apply_vars(_prop)
             if value is None:
                 pass
-            elif isinstance(value, basestring):
+            elif isinstance(value, six.string_types):
                 # TODO kill this branch
                 pass
             else:
diff --git a/scss/__main__.py b/scss/__main__.py
index c96ee59..792ead7 100644
--- a/scss/__main__.py
+++ b/scss/__main__.py
@@ -1,3 +1,3 @@
-import tool
+import scss.tool
 
-tool.main()
+scss.tool.main()
diff --git a/scss/expression.py b/scss/expression.py
index 65eb4b3..6bd2bec 100644
--- a/scss/expression.py
+++ b/scss/expression.py
@@ -5,6 +5,8 @@ import logging
 import operator
 import re
 
+import six
+
 import scss.config as config
 from scss.cssdefs import COLOR_NAMES, is_builtin_css_function, _expr_glob_re, _interpolate_re, _variable_re
 from scss.types import BooleanValue, ColorValue, ListValue, Null, NumberValue, ParserValue, String
@@ -54,7 +56,7 @@ class Calculator(object):
         return cont
 
     def apply_vars(self, cont):
-        if isinstance(cont, basestring) and '$' in cont:
+        if isinstance(cont, six.string_types) and '$' in cont:
             try:
                 # Optimization: the full cont is a variable in the context,
                 cont = self.namespace.variable(cont)
@@ -93,7 +95,7 @@ class Calculator(object):
     # TODO only used by magic-import...?
     def interpolate(self, var):
         value = self.namespace.variable(var)
-        if var != value and isinstance(value, basestring):
+        if var != value and isinstance(value, six.string_types):
             _vi = self.evaluate_expression(value)
             if _vi is not None:
                 value = _vi
@@ -103,7 +105,7 @@ class Calculator(object):
     def evaluate_expression(self, expr):
         results = None
 
-        if not isinstance(expr, basestring):
+        if not isinstance(expr, six.string_types):
             results = expr
 
         if results is None:
@@ -112,7 +114,7 @@ class Calculator(object):
             except KeyError:
                 pass
 
-            if not isinstance(expr, basestring):
+            if not isinstance(expr, six.string_types):
                 results = expr
 
         ast = None
@@ -128,7 +130,7 @@ class Calculator(object):
                 except SyntaxError:
                     if config.DEBUG:
                         raise
-                except Exception, e:
+                except Exception:
                     # TODO hoist me up since the rule is gone
                     #log.exception("Exception raised: %s in `%s' (%s)", e, expr, rule.file_and_line)
                     if config.DEBUG:
@@ -310,7 +312,7 @@ class Variable(Expression):
             raise
             return self.name
         else:
-            if isinstance(value, basestring):
+            if isinstance(value, six.string_types):
                 evald = calculator.evaluate_expression(value)
                 if evald is not None:
                     return evald
diff --git a/scss/functions/compass/gradients.py b/scss/functions/compass/gradients.py
index e97465e..6698283 100644
--- a/scss/functions/compass/gradients.py
+++ b/scss/functions/compass/gradients.py
@@ -7,6 +7,8 @@ from __future__ import absolute_import
 import base64
 import logging
 
+import six
+
 from scss.functions.library import FunctionLibrary
 from scss.functions.compass.helpers import opposite_position, position
 from scss.types import ColorValue, ListValue, NumberValue, StringValue
@@ -23,7 +25,7 @@ def __color_stops(percentages, *args):
     if len(args) == 1:
         if isinstance(args[0], (list, tuple, ListValue)):
             return ListValue(args[0]).values()
-        elif isinstance(args[0], (StringValue, basestring)):
+        elif isinstance(args[0], (StringValue, six.string_types)):
             color_stops = []
             colors = split_params(args[0].value)
             for color in colors:
@@ -160,7 +162,7 @@ def color_stops_in_percentages(*args):
 
 def _get_gradient_position_and_angle(args):
     for arg in args:
-        if isinstance(arg, (StringValue, NumberValue, basestring)):
+        if isinstance(arg, (StringValue, NumberValue, six.string_types)):
             _arg = [arg]
         elif isinstance(arg, (list, tuple, ListValue)):
             _arg = arg
@@ -190,7 +192,7 @@ def _get_gradient_position_and_angle(args):
 
 def _get_gradient_shape_and_size(args):
     for arg in args:
-        if isinstance(arg, (StringValue, NumberValue, basestring)):
+        if isinstance(arg, (StringValue, NumberValue, six.string_types)):
             _arg = [arg]
         elif isinstance(arg, (list, tuple, ListValue)):
             _arg = arg
@@ -345,7 +347,7 @@ def radial_svg_gradient(*args):
         args = ListValue(args[0]).values()
     color_stops = args
     center = None
-    if isinstance(args[-1], (StringValue, NumberValue, basestring)):
+    if isinstance(args[-1], (StringValue, NumberValue, six.string_types)):
         center = args[-1]
         color_stops = args[:-1]
     color_stops = __color_stops(False, *color_stops)
@@ -363,7 +365,7 @@ def linear_svg_gradient(*args):
         args = ListValue(args[0]).values()
     color_stops = args
     start = None
-    if isinstance(args[-1], (StringValue, NumberValue, basestring)):
+    if isinstance(args[-1], (StringValue, NumberValue, six.string_types)):
         start = args[-1]
         color_stops = args[:-1]
     color_stops = __color_stops(False, *color_stops)
diff --git a/scss/functions/compass/images.py b/scss/functions/compass/images.py
index 45fed74..1eeea38 100644
--- a/scss/functions/compass/images.py
+++ b/scss/functions/compass/images.py
@@ -1,6 +1,7 @@
 """Image utilities ported from Compass."""
 
 from __future__ import absolute_import
+from __future__ import print_function
 
 import base64
 import hashlib
@@ -9,19 +10,15 @@ import mimetypes
 import os.path
 import time
 
+import six
+
 from scss import config
 from scss.functions.compass import _image_size_cache
+from scss.functions.compass.helpers import add_cache_buster
 from scss.functions.library import FunctionLibrary
 from scss.types import ColorValue, ListValue, NumberValue, StringValue
 from scss.util import escape
 
-from scss.functions.compass.helpers import add_cache_buster
-
-try:
-    from cStringIO import StringIO
-except ImportError:
-    from StringIO import StringIO
-
 try:
     from PIL import Image
 except ImportError:
@@ -153,7 +150,7 @@ def _image_url(path, only_path=False, cache_buster=True, dst_color=None, src_col
                 if cache_buster:
                     url = add_cache_buster(url, filetime)
             if inline:
-                output = StringIO()
+                output = six.BytesIO()
                 new_image.save(output, format='PNG')
                 contents = output.getvalue()
                 output.close()
diff --git a/scss/functions/core.py b/scss/functions/core.py
index 6569726..887662b 100644
--- a/scss/functions/core.py
+++ b/scss/functions/core.py
@@ -9,6 +9,8 @@ import logging
 import math
 import operator
 
+import six
+
 from scss.cssdefs import _variable_re
 from scss.functions.library import FunctionLibrary
 from scss.types import BooleanValue, ColorValue, ListValue, NumberValue, QuotedStringValue, StringValue, String
@@ -560,5 +562,5 @@ def comparable(number1, number2):
 @register('if', 2)
 @register('if', 3)
 def if_(condition, if_true, if_false=''):
-    condition = bool(False if not condition or isinstance(condition, basestring) and (condition in ('0', 'false', 'undefined') or _variable_re.match(condition)) else condition)
+    condition = bool(False if not condition or isinstance(condition, six.string_types) and (condition in ('0', 'false', 'undefined') or _variable_re.match(condition)) else condition)
     return if_true.__class__(if_true) if condition else if_true.__class__(if_false)
diff --git a/scss/functions/extra.py b/scss/functions/extra.py
index 1ce8f8c..6f4b274 100644
--- a/scss/functions/extra.py
+++ b/scss/functions/extra.py
@@ -8,17 +8,14 @@ import logging
 import os.path
 import random
 
+import six
+
 from scss import config
 from scss.functions.library import FunctionLibrary
 from scss.types import ColorValue, NumberValue, StringValue, ListValue
 from scss.util import escape
 
 try:
-    from cStringIO import StringIO
-except ImportError:
-    from StringIO import StringIO
-
-try:
     from PIL import Image, ImageDraw
 except ImportError:
     try:
@@ -325,7 +322,7 @@ def background_noise(density=None, opacity=None, size=None, monochrome=False, in
             inline = True  # Retry inline version
         url = '%s%s' % (config.ASSETS_URL, asset_file)
     if inline:
-        output = StringIO()
+        output = six.BytesIO()
         new_image.save(output, format='PNG')
         contents = output.getvalue()
         output.close()
@@ -409,7 +406,7 @@ def background_brushed(density=None, intensity=None, color=None, opacity=None, s
             inline = True  # Retry inline version
         url = '%s%s' % (config.ASSETS_URL, asset_file)
     if inline:
-        output = StringIO()
+        output = six.BytesIO()
         new_image.save(output, format='PNG')
         contents = output.getvalue()
         output.close()
@@ -476,7 +473,7 @@ def _grid_image(left_gutter, width, right_gutter, height, columns=1, grid_color=
             inline = True  # Retry inline version
         url = '%s%s' % (config.ASSETS_URL, asset_file)
     if inline:
-        output = StringIO()
+        output = six.BytesIO()
         new_image.save(output, format='PNG')
         contents = output.getvalue()
         output.close()
@@ -501,7 +498,7 @@ def image_color(color, width=1, height=1):
         size=(w, h),
         color=(c[0], c[1], c[2], int(c[3] * 255.0))
     )
-    output = StringIO()
+    output = six.BytesIO()
     new_image.save(output, format='PNG')
     contents = output.getvalue()
     output.close()
diff --git a/scss/rule.py b/scss/rule.py
index a650c4f..5b7cbfc 100644
--- a/scss/rule.py
+++ b/scss/rule.py
@@ -1,8 +1,13 @@
+from __future__ import absolute_import
+from __future__ import print_function
+
+import six
+
 from scss.cssdefs import _has_placeholder_re
 
 
 def normalize_var(name):
-    if isinstance(name, basestring):
+    if isinstance(name, six.string_types):
         return name.replace('_', '-')
     else:
         return name
@@ -79,7 +84,7 @@ class Namespace(object):
 
     def set_variable(self, name, value):
         name = normalize_var(name)
-        assert not (isinstance(value, basestring) and value.startswith('$'))
+        assert not (isinstance(value, six.string_types) and value.startswith('$'))
         #assert isinstance(value, Value)
         self._variables[name] = value
 
diff --git a/scss/tool.py b/scss/tool.py
index b08d9be..c11e6c3 100644
--- a/scss/tool.py
+++ b/scss/tool.py
@@ -1,5 +1,6 @@
 #!/usr/bin/env python
 from __future__ import absolute_import
+from __future__ import print_function
 
 import logging
 import os
@@ -109,7 +110,7 @@ def main():
         import doctest
         doctest.testfile('tests/tests.rst')
     elif options.version:
-        print BUILD_INFO
+        print(BUILD_INFO)
     elif options.interactive:
         from pprint import pprint
         try:
@@ -131,7 +132,7 @@ def main():
         options = css.scss_opts
         source_file = SourceFile.from_string('', '<shell>', line_numbers=False)
         rule = SassRule(source_file, context=context, options=options, is_sass=is_sass)
-        print "Welcome to %s interactive shell" % BUILD_INFO
+        print("Welcome to %s interactive shell" % (BUILD_INFO,))
         while True:
             try:
                 s = raw_input('>>> ').strip()
@@ -171,7 +172,7 @@ def main():
                             if code:
                                 final_cont += code
                         final_cont = css.post_process(final_cont)
-                        print final_cont
+                        print(final_cont)
                         continue
                 elif s == 'ls' or s.startswith('show(') or s.startswith('show ') or s.startswith('ls(') or s.startswith('ls '):
                     m = re.match(r'(?:show|ls)(\()?\s*([^,/\\) ]*)(?:[,/\\ ]([^,/\\ )]+))*(?(1)\))', s, re.IGNORECASE)
@@ -218,9 +219,9 @@ def main():
                                     fn_name, _, _ = k.partition(':')
                                     if fn_name not in seen:
                                         seen.add(fn_name)
-                                        print fn_name + '(' + ', '.join(p + (': ' + mixin[1].get(p) if p in mixin[1] else '') for p in mixin[0]) + ') {'
-                                        print '  ' + '\n  '.join(l for l in mixin[2].split('\n'))
-                                        print '}'
+                                        print(fn_name + '(' + ', '.join(p + (': ' + mixin[1].get(p) if p in mixin[1] else '') for p in mixin[0]) + ') {')
+                                        print('  ' + '\n  '.join(l for l in mixin[2].split('\n')))
+                                        print('}')
                             else:
                                 d = dict((k[len(name) + 2:].split(':')[0], v) for k, v in options.items() if k.startswith('@' + name + ' '))
                                 pprint(sorted(d))
@@ -233,8 +234,8 @@ def main():
                     continue
                 s = to_str(css.calculator.calculate(s, context, rule))
                 s = css.post_process(s)
-                print s
-        print "Bye!"
+                print(s)
+        print("Bye!")
     elif options.watch:
         import time
         try:
@@ -285,7 +286,7 @@ def main():
                 else:
                     dest_path = os.path.join(os.path.dirname(src_path), fname)
 
-                print "Compiling %s => %s" % (src_path, dest_path)
+                print("Compiling %s => %s" % (src_path, dest_path))
                 dest_file = open(dest_path, 'w')
                 dest_file.write(self.css.compile(scss_file=src_path))
 
@@ -329,7 +330,7 @@ def main():
             output.write(css.compile(sys.stdin.read(), is_sass=options.is_sass))
 
         for f, t in profiling.items():
-            print >>sys.stderr, "%s took %03fs" % (f, t)
+            sys.stderr.write("%s took %03fs" % (f, t))
 
 if __name__ == "__main__":
     main()
diff --git a/scss/util.py b/scss/util.py
index fae1868..57d568e 100644
--- a/scss/util.py
+++ b/scss/util.py
@@ -1,12 +1,11 @@
+from __future__ import absolute_import
+from __future__ import print_function
+
 import re
 import sys
 import time
 
-import cProfile
-try:
-    from cStringIO import StringIO
-except:
-    from StringIO import StringIO
+import six
 
 from scss import config
 
@@ -112,10 +111,11 @@ def print_timing(level=0):
 ################################################################################
 # Profiler decorator
 def profile(fn):
+    import cProfile
     import pstats
     def wrapper(*args, **kwargs):
         profiler = cProfile.Profile()
-        stream = StringIO()
+        stream = six.StringIO()
         profiler.enable()
         try:
             res = fn(*args, **kwargs)
diff --git a/setup.py b/setup.py
index 2bd31bc..85de7db 100644
--- a/setup.py
+++ b/setup.py
@@ -100,6 +100,9 @@ def run_setup(with_binary):
             "Topic :: Text Processing :: Markup",
             "Topic :: Software Development :: Libraries :: Python Modules"
         ],
+        requires=[
+            'six',
+        ],
         packages=[
             'scss',
             'scss.functions',