diff --git a/MANIFEST.in b/MANIFEST.in
index 4f99104..9f78903 100644
--- a/MANIFEST.in
+++ b/MANIFEST.in
@@ -1,9 +1,7 @@
-recursive-include tests *
-recursive-include talon *
 recursive-exclude tests *.pyc *~
 recursive-exclude talon *.pyc *~
 include train.data
 include classifier
 include LICENSE
 include MANIFEST.in
-include README.rst
\ No newline at end of file
+include README.rst
diff --git a/setup.py b/setup.py
index 8be1da5..e276339 100755
--- a/setup.py
+++ b/setup.py
@@ -1,4 +1,31 @@
+from __future__ import absolute_import
 from setuptools import setup, find_packages
+from setuptools.command.install import install
+
+
+class InstallCommand(install):
+    user_options = install.user_options + [
+        ('no-ml', None, "Don't install without Machine Learning modules."),
+    ]
+
+    boolean_options = install.boolean_options + ['no-ml']
+
+    def initialize_options(self):
+        install.initialize_options(self)
+        self.no_ml = None
+
+    def finalize_options(self):
+        install.finalize_options(self)
+        if self.no_ml:
+            dist = self.distribution
+            dist.packages=find_packages(exclude=[
+                'tests',
+                'tests.*',
+                'talon.signature',
+                'talon.signature.*',
+            ])
+            for not_required in ['numpy', 'scipy', 'scikit-learn==0.16.1']:
+                dist.install_requires.remove(not_required)
 
 
 setup(name='talon',
@@ -10,7 +37,10 @@ setup(name='talon',
       author_email='admin@mailgunhq.com',
       url='https://github.com/mailgun/talon',
       license='APACHE2',
-      packages=find_packages(exclude=['tests']),
+      cmdclass={
+          'install': InstallCommand,
+      },
+      packages=find_packages(exclude=['tests', 'tests.*']),
       include_package_data=True,
       zip_safe=True,
       install_requires=[
@@ -21,7 +51,8 @@ setup(name='talon',
           "scikit-learn==0.16.1", # pickled versions of classifier, else rebuild
           'chardet>=1.0.1',
           'cchardet>=0.3.5',
-          'cssselect'
+          'cssselect',
+          'six>=1.10.0',
           ],
       tests_require=[
           "mock",
diff --git a/talon/__init__.py b/talon/__init__.py
index 13e46a8..7060f5b 100644
--- a/talon/__init__.py
+++ b/talon/__init__.py
@@ -1,7 +1,13 @@
+from __future__ import absolute_import
 from talon.quotations import register_xpath_extensions
-from talon import signature
+try:
+    from talon import signature
+    ML_ENABLED = True
+except ImportError:
+    ML_ENABLED = False
 
 
 def init():
     register_xpath_extensions()
-    signature.initialize()
+    if ML_ENABLED:
+        signature.initialize()
diff --git a/talon/constants.py b/talon/constants.py
index 68fa04c..0e7276d 100644
--- a/talon/constants.py
+++ b/talon/constants.py
@@ -1,3 +1,4 @@
+from __future__ import absolute_import
 import regex as re
 
 
diff --git a/talon/html_quotations.py b/talon/html_quotations.py
index 1af78ac..4aa7e74 100644
--- a/talon/html_quotations.py
+++ b/talon/html_quotations.py
@@ -3,6 +3,7 @@ The module's functions operate on message bodies trying to extract original
 messages (without quoted messages) from html
 """
 
+from __future__ import absolute_import
 import regex as re
 
 
diff --git a/talon/quotations.py b/talon/quotations.py
index ff23daa..d9dba21 100644
--- a/talon/quotations.py
+++ b/talon/quotations.py
@@ -5,6 +5,7 @@ The module's functions operate on message bodies trying to extract
 original messages (without quoted messages)
 """
 
+from __future__ import absolute_import
 import regex as re
 import logging
 from copy import deepcopy
@@ -13,6 +14,8 @@ from lxml import html, etree
 
 from talon.utils import get_delimiter, html_to_text
 from talon import html_quotations
+from six.moves import range
+import six
 
 
 log = logging.getLogger(__name__)
@@ -191,7 +194,7 @@ def mark_message_lines(lines):
     >>> mark_message_lines(['answer', 'From: foo@bar.com', '', '> question'])
     'tsem'
     """
-    markers = bytearray(len(lines))
+    markers = ['e' for _ in lines]
     i = 0
     while i < len(lines):
         if not lines[i].strip():
@@ -207,7 +210,7 @@ def mark_message_lines(lines):
             if splitter:
                 # append as many splitter markers as lines in splitter
                 splitter_lines = splitter.group().splitlines()
-                for j in xrange(len(splitter_lines)):
+                for j in range(len(splitter_lines)):
                     markers[i + j] = 's'
 
                 # skip splitter lines
@@ -217,7 +220,7 @@ def mark_message_lines(lines):
                 markers[i] = 't'
         i += 1
 
-    return markers
+    return ''.join(markers)
 
 
 def process_marked_lines(lines, markers, return_flags=[False, -1, -1]):
@@ -231,6 +234,7 @@ def process_marked_lines(lines, markers, return_flags=[False, -1, -1]):
     return_flags = [were_lines_deleted, first_deleted_line,
                     last_deleted_line]
     """
+    markers = ''.join(markers)
     # if there are no splitter there should be no markers
     if 's' not in markers and not re.search('(me*){3}', markers):
         markers = markers.replace('m', 't')
@@ -276,10 +280,15 @@ def preprocess(msg_body, delimiter, content_type='text/plain'):
     Replaces link brackets so that they couldn't be taken for quotation marker.
     Splits line in two if splitter pattern preceded by some text on the same
     line (done only for 'On <date> <person> wrote:' pattern).
+
+    Converts msg_body into a unicode.
     """
     # normalize links i.e. replace '<', '>' wrapping the link with some symbols
     # so that '>' closing the link couldn't be mistakenly taken for quotation
     # marker.
+    if isinstance(msg_body, bytes):
+        msg_body = msg_body.decode('utf8')
+
     def link_wrapper(link):
         newline_index = msg_body[:link.start()].rfind("\n")
         if msg_body[newline_index + 1] == ">":
@@ -342,11 +351,41 @@ def extract_from_html(msg_body):
     then extracting quotations from text,
     then checking deleted checkpoints,
     then deleting necessary tags.
+
+    Returns a unicode string.
     """
-    if msg_body.strip() == '':
+    if isinstance(msg_body, six.text_type):
+        msg_body = msg_body.encode('utf8')
+    elif not isinstance(msg_body, bytes):
+        msg_body = msg_body.encode('ascii')
+
+    result = _extract_from_html(msg_body)
+    if isinstance(result, bytes):
+        result = result.decode('utf8')
+
+    return result
+
+
+def _extract_from_html(msg_body):
+    """
+    Extract not quoted message from provided html message body
+    using tags and plain text algorithm.
+
+    Cut out the 'blockquote', 'gmail_quote' tags.
+    Cut Microsoft quotations.
+
+    Then use plain text algorithm to cut out splitter or
+    leftover quotation.
+    This works by adding checkpoint text to all html tags,
+    then converting html to text,
+    then extracting quotations from text,
+    then checking deleted checkpoints,
+    then deleting necessary tags.
+    """
+    if msg_body.strip() == b'':
         return msg_body
 
-    msg_body = msg_body.replace('\r\n', '').replace('\n', '')
+    msg_body = msg_body.replace(b'\r\n', b'').replace(b'\n', b'')
     html_tree = html.document_fromstring(
         msg_body,
         parser=html.HTMLParser(encoding="utf-8")
@@ -388,7 +427,7 @@ def extract_from_html(msg_body):
     lines_were_deleted, first_deleted, last_deleted = return_flags
     if lines_were_deleted:
         #collect checkpoints from deleted lines
-        for i in xrange(first_deleted, last_deleted):
+        for i in range(first_deleted, last_deleted):
             for checkpoint in line_checkpoints[i]:
                 quotation_checkpoints[checkpoint] = True
     else:
diff --git a/talon/signature/__init__.py b/talon/signature/__init__.py
index a871447..fc60e1d 100644
--- a/talon/signature/__init__.py
+++ b/talon/signature/__init__.py
@@ -20,6 +20,7 @@ trained against, don't forget to regenerate:
 * signature/data/classifier
 """
 
+from __future__ import absolute_import
 import os
 
 from . import extraction
diff --git a/talon/signature/bruteforce.py b/talon/signature/bruteforce.py
index d3493bb..7f666bd 100644
--- a/talon/signature/bruteforce.py
+++ b/talon/signature/bruteforce.py
@@ -1,3 +1,4 @@
+from __future__ import absolute_import
 import logging
 
 import regex as re
@@ -111,7 +112,7 @@ def extract_signature(msg_body):
 
             return (stripped_body.strip(),
                     signature.strip())
-    except Exception, e:
+    except Exception as e:
         log.exception('ERROR extracting signature')
         return (msg_body, None)
 
diff --git a/talon/signature/extraction.py b/talon/signature/extraction.py
index 995ad27..3259171 100644
--- a/talon/signature/extraction.py
+++ b/talon/signature/extraction.py
@@ -1,5 +1,6 @@
 # -*- coding: utf-8 -*-
 
+from __future__ import absolute_import
 import logging
 
 import regex as re
diff --git a/talon/signature/learning/classifier.py b/talon/signature/learning/classifier.py
index 9ce5e75..8ec3228 100644
--- a/talon/signature/learning/classifier.py
+++ b/talon/signature/learning/classifier.py
@@ -5,6 +5,7 @@ The classifier could be used to detect if a certain line of the message
 body belongs to the signature.
 """
 
+from __future__ import absolute_import
 from numpy import genfromtxt
 from sklearn.svm import LinearSVC
 from sklearn.externals import joblib
diff --git a/talon/signature/learning/dataset.py b/talon/signature/learning/dataset.py
index b0a9f45..308995b 100644
--- a/talon/signature/learning/dataset.py
+++ b/talon/signature/learning/dataset.py
@@ -16,11 +16,13 @@ suffix and the corresponding sender file has the same name except for the
 suffix which should be `_sender`.
 """
 
+from __future__ import absolute_import
 import os
 import regex as re
 
 from talon.signature.constants import SIGNATURE_MAX_LINES
 from talon.signature.learning.featurespace import build_pattern, features
+from six.moves import range
 
 
 SENDER_SUFFIX = '_sender'
@@ -144,7 +146,7 @@ def build_extraction_dataset(folder, dataset_filename,
             if not sender or not msg:
                 continue
             lines = msg.splitlines()
-            for i in xrange(1, min(SIGNATURE_MAX_LINES,
+            for i in range(1, min(SIGNATURE_MAX_LINES,
                                    len(lines)) + 1):
                 line = lines[-i]
                 label = -1
diff --git a/talon/signature/learning/featurespace.py b/talon/signature/learning/featurespace.py
index 60676f9..649e859 100644
--- a/talon/signature/learning/featurespace.py
+++ b/talon/signature/learning/featurespace.py
@@ -7,9 +7,12 @@ The body and the message sender string are converted into unicode before
 applying features to them.
 """
 
+from __future__ import absolute_import
 from talon.signature.constants import (SIGNATURE_MAX_LINES,
                                        TOO_LONG_SIGNATURE_LINE)
 from talon.signature.learning.helpers import *
+from six.moves import zip
+from functools import reduce
 
 
 def features(sender=''):
diff --git a/talon/signature/learning/helpers.py b/talon/signature/learning/helpers.py
index 7085a74..f94c688 100644
--- a/talon/signature/learning/helpers.py
+++ b/talon/signature/learning/helpers.py
@@ -6,6 +6,7 @@
 
 """
 
+from __future__ import absolute_import
 import unicodedata
 import regex as re
 
diff --git a/talon/utils.py b/talon/utils.py
index dc47622..02a7a92 100644
--- a/talon/utils.py
+++ b/talon/utils.py
@@ -1,5 +1,6 @@
 # coding:utf-8
 
+from __future__ import absolute_import
 import logging
 from random import shuffle
 import chardet
@@ -10,6 +11,7 @@ from lxml import html
 from lxml.cssselect import CSSSelector
 
 from talon.constants import RE_DELIMITER
+import six
 
 
 def safe_format(format_string, *args, **kwargs):
@@ -28,7 +30,7 @@ def safe_format(format_string, *args, **kwargs):
     except (UnicodeEncodeError, UnicodeDecodeError):
         format_string = to_utf8(format_string)
         args = [to_utf8(p) for p in args]
-        kwargs = {k: to_utf8(v) for k, v in kwargs.iteritems()}
+        kwargs = {k: to_utf8(v) for k, v in six.iteritems(kwargs)}
         return format_string.format(*args, **kwargs)
 
     # ignore other errors
@@ -45,9 +47,9 @@ def to_unicode(str_or_unicode, precise=False):
         u'привет'
     If `precise` flag is True, tries to guess the correct encoding first.
     """
-    encoding = quick_detect_encoding(str_or_unicode) if precise else 'utf-8'
-    if isinstance(str_or_unicode, str):
-        return unicode(str_or_unicode, encoding, 'replace')
+    if not isinstance(str_or_unicode, six.text_type):
+        encoding = quick_detect_encoding(str_or_unicode) if precise else 'utf-8'
+        return six.text_type(str_or_unicode, encoding, 'replace')
     return str_or_unicode
 
 
@@ -57,11 +59,12 @@ def detect_encoding(string):
 
     Defaults to UTF-8.
     """
+    assert isinstance(string, bytes)
     try:
         detected = chardet.detect(string)
         if detected:
             return detected.get('encoding') or 'utf-8'
-    except Exception, e:
+    except Exception as e:
         pass
     return 'utf-8'
 
@@ -72,11 +75,12 @@ def quick_detect_encoding(string):
 
     Uses cchardet. Fallbacks to detect_encoding.
     """
+    assert isinstance(string, bytes)
     try:
         detected = cchardet.detect(string)
         if detected:
             return detected.get('encoding') or detect_encoding(string)
-    except Exception, e:
+    except Exception as e:
         pass
     return detect_encoding(string)
 
@@ -87,7 +91,7 @@ def to_utf8(str_or_unicode):
     >>> utils.to_utf8(u'hi')
         'hi'
     """
-    if isinstance(str_or_unicode, unicode):
+    if not isinstance(str_or_unicode, six.text_type):
         return str_or_unicode.encode("utf-8", "ignore")
     return str(str_or_unicode)
 
@@ -119,8 +123,11 @@ def html_to_text(string):
         1. the string is expected to contain UTF-8 encoded HTML!
         2. returns utf-8 encoded str (not unicode)
     """
+    if isinstance(string, six.text_type):
+        string = string.encode('utf8')
+
     s = _prepend_utf8_declaration(string)
-    s = s.replace("\n", "")
+    s = s.replace(b"\n", b"")
 
     tree = html.fromstring(s)
 
@@ -155,7 +162,7 @@ def html_to_text(string):
 def _contains_charset_spec(s):
     """Return True if the first 4KB contain charset spec
     """
-    return s.lower().find('html; charset=', 0, 4096) != -1
+    return s.lower().find(b'html; charset=', 0, 4096) != -1
 
 
 def _prepend_utf8_declaration(s):
@@ -173,11 +180,11 @@ def _rm_excessive_newlines(s):
 def _encode_utf8(s):
     """Encode in 'utf-8' if unicode
     """
-    return s.encode('utf-8') if isinstance(s, unicode) else s
+    return s.encode('utf-8') if isinstance(s, six.text_type) else s
 
 
-_UTF8_DECLARATION = ('<meta http-equiv="Content-Type" content="text/html;'
-                     'charset=utf-8">')
+_UTF8_DECLARATION = (b'<meta http-equiv="Content-Type" content="text/html;'
+                     b'charset=utf-8">')
 
 
 _BLOCKTAGS  = ['div', 'p', 'ul', 'li', 'h1', 'h2', 'h3']
diff --git a/tests/__init__.py b/tests/__init__.py
index 8bd86cb..8fdebd6 100644
--- a/tests/__init__.py
+++ b/tests/__init__.py
@@ -1,3 +1,4 @@
+from __future__ import absolute_import
 from nose.tools import *
 from mock import *
 
diff --git a/tests/html_quotations_test.py b/tests/html_quotations_test.py
index 4002d0f..c155cbb 100644
--- a/tests/html_quotations_test.py
+++ b/tests/html_quotations_test.py
@@ -1,5 +1,6 @@
 # -*- coding: utf-8 -*-
 
+from __future__ import absolute_import
 from . import *
 from . fixtures import *
 
@@ -305,6 +306,7 @@ def extract_reply_and_check(filename):
     msg_body = f.read()
     reply = quotations.extract_from_html(msg_body)
     plain_reply = u.html_to_text(reply)
+    plain_reply = plain_reply.decode('utf8')
 
     eq_(RE_WHITESPACE.sub('', "Hi. I am fine.\n\nThanks,\nAlex"),
         RE_WHITESPACE.sub('', plain_reply))
diff --git a/tests/quotations_test.py b/tests/quotations_test.py
index 7184368..e5ed041 100644
--- a/tests/quotations_test.py
+++ b/tests/quotations_test.py
@@ -1,5 +1,6 @@
 # -*- coding: utf-8 -*-
 
+from __future__ import absolute_import
 from . import *
 from . fixtures import *
 
diff --git a/tests/signature/bruteforce_test.py b/tests/signature/bruteforce_test.py
index 09665fe..382615b 100644
--- a/tests/signature/bruteforce_test.py
+++ b/tests/signature/bruteforce_test.py
@@ -1,5 +1,6 @@
 # -*- coding: utf-8 -*-
 
+from __future__ import absolute_import
 from .. import *
 
 from talon.signature import bruteforce
diff --git a/tests/signature/extraction_test.py b/tests/signature/extraction_test.py
index a055064..72e962f 100644
--- a/tests/signature/extraction_test.py
+++ b/tests/signature/extraction_test.py
@@ -1,5 +1,6 @@
 # -*- coding: utf-8 -*-
 
+from __future__ import absolute_import
 from .. import *
 
 import os
@@ -8,6 +9,7 @@ from talon.signature.learning import dataset
 from talon import signature
 from talon.signature import extraction as e
 from talon.signature import bruteforce
+from six.moves import range
 
 
 def test_message_shorter_SIGNATURE_MAX_LINES():
@@ -127,20 +129,20 @@ def test_mark_lines():
 
 def test_process_marked_lines():
     # no signature found
-    eq_((range(5), None), e._process_marked_lines(range(5), 'telt'))
+    eq_((list(range(5)), None), e._process_marked_lines(list(range(5)), 'telt'))
 
     # signature in the middle of the text
-    eq_((range(9), None), e._process_marked_lines(range(9), 'tesestelt'))
+    eq_((list(range(9)), None), e._process_marked_lines(list(range(9)), 'tesestelt'))
 
     # long line splits signature
-    eq_((range(7), [7, 8]),
-        e._process_marked_lines(range(9), 'tsslsless'))
+    eq_((list(range(7)), [7, 8]),
+        e._process_marked_lines(list(range(9)), 'tsslsless'))
 
-    eq_((range(20), [20]),
-        e._process_marked_lines(range(21), 'ttttttstttesllelelets'))
+    eq_((list(range(20)), [20]),
+        e._process_marked_lines(list(range(21)), 'ttttttstttesllelelets'))
 
     # some signature lines could be identified as text
-    eq_(([0], range(1, 9)), e._process_marked_lines(range(9), 'tsetetest'))
+    eq_(([0], list(range(1, 9))), e._process_marked_lines(list(range(9)), 'tsetetest'))
 
-    eq_(([], range(5)),
-        e._process_marked_lines(range(5), "ststt"))
+    eq_(([], list(range(5))),
+        e._process_marked_lines(list(range(5)), "ststt"))
diff --git a/tests/signature/learning/dataset_test.py b/tests/signature/learning/dataset_test.py
index 42d8ae6..8e15275 100644
--- a/tests/signature/learning/dataset_test.py
+++ b/tests/signature/learning/dataset_test.py
@@ -1,5 +1,6 @@
 # -*- coding: utf-8 -*-
 
+from __future__ import absolute_import
 from ... import *
 import os
 
diff --git a/tests/signature/learning/featurespace_test.py b/tests/signature/learning/featurespace_test.py
index 70df62b..dd9f110 100644
--- a/tests/signature/learning/featurespace_test.py
+++ b/tests/signature/learning/featurespace_test.py
@@ -1,5 +1,6 @@
 # -*- coding: utf-8 -*-
 
+from __future__ import absolute_import
 from ... import *
 
 from talon.signature.learning import featurespace as fs
diff --git a/tests/signature/learning/helpers_test.py b/tests/signature/learning/helpers_test.py
index 704db4e..94f186f 100644
--- a/tests/signature/learning/helpers_test.py
+++ b/tests/signature/learning/helpers_test.py
@@ -1,11 +1,13 @@
 # -*- coding: utf-8 -*-
 
+from __future__ import absolute_import
 from ... import *
 
 import regex as re
 
 from talon.signature.learning import helpers as h
 from talon.signature.learning.helpers import *
+from six.moves import range
 
 # First testing regex constants.
 VALID = '''
@@ -154,7 +156,7 @@ def test_extract_names():
         # check that extracted names could be compiled
         try:
             re.compile("|".join(extracted_names))
-        except Exception, e:
+        except Exception as e:
             ok_(False, ("Failed to compile extracted names {}"
                         "\n\nReason: {}").format(extracted_names, e))
         if expected_names:
@@ -204,7 +206,7 @@ def test_has_signature():
                         'sender@example.com'))
     assert_false(h.has_signature('http://www.example.com/555-555-5555',
                                  'sender@example.com'))
-    long_line = ''.join(['q' for e in xrange(28)])
+    long_line = ''.join(['q' for e in range(28)])
     assert_false(h.has_signature(long_line + ' sender', 'sender@example.com'))
     # wont crash on an empty string
     assert_false(h.has_signature('', ''))
diff --git a/tests/text_quotations_test.py b/tests/text_quotations_test.py
index 70e1bfa..aed2ce8 100644
--- a/tests/text_quotations_test.py
+++ b/tests/text_quotations_test.py
@@ -1,5 +1,6 @@
 # -*- coding: utf-8 -*-
 
+from __future__ import absolute_import
 from . import *
 from . fixtures import *
 
@@ -7,6 +8,9 @@ import os
 
 import email.iterators
 from talon import quotations
+import six
+from six.moves import range
+from six import StringIO
 
 
 @patch.object(quotations, 'MAX_LINES_COUNT', 1)
@@ -138,7 +142,7 @@ def _check_pattern_original_message(original_message_indicator):
 -----{}-----
 
 Test"""
-    eq_('Test reply', quotations.extract_from_plain(msg_body.format(unicode(original_message_indicator))))
+    eq_('Test reply', quotations.extract_from_plain(msg_body.format(six.text_type(original_message_indicator))))
 
 def test_english_original_message():
     _check_pattern_original_message('Original Message')
@@ -662,6 +666,15 @@ def test_preprocess_postprocess_2_links():
     eq_(msg_body, quotations.extract_from_plain(msg_body))
 
 
+def body_iterator(msg, decode=False):
+    for subpart in msg.walk():
+        payload = subpart.get_payload(decode=decode)
+        if isinstance(payload, six.text_type):
+            yield payload
+        else:
+            yield payload.decode('utf8')
+
+
 def test_standard_replies():
     for filename in os.listdir(STANDARD_REPLIES):
         filename = os.path.join(STANDARD_REPLIES, filename)
@@ -669,8 +682,8 @@ def test_standard_replies():
             continue
         with open(filename) as f:
             message = email.message_from_file(f)
-            body = email.iterators.typed_subpart_iterator(message, subtype='plain').next()
-            text = ''.join(email.iterators.body_line_iterator(body, True))
+            body = next(email.iterators.typed_subpart_iterator(message, subtype='plain'))
+            text = ''.join(body_iterator(body, True))
 
             stripped_text = quotations.extract_from_plain(text)
             reply_text_fn = filename[:-4] + '_reply_text'
diff --git a/tests/utils_test.py b/tests/utils_test.py
index c77f0a6..37f4d7b 100644
--- a/tests/utils_test.py
+++ b/tests/utils_test.py
@@ -1,9 +1,11 @@
 # coding:utf-8
 
+from __future__ import absolute_import
 from . import *
 
 from talon import utils as u
 import cchardet
+import six
 
 
 def test_get_delimiter():
@@ -14,49 +16,49 @@ def test_get_delimiter():
 
 def test_unicode():
     eq_ (u'hi', u.to_unicode('hi'))
-    eq_ (type(u.to_unicode('hi')), unicode )
-    eq_ (type(u.to_unicode(u'hi')), unicode )
-    eq_ (type(u.to_unicode('привет')), unicode )
-    eq_ (type(u.to_unicode(u'привет')), unicode )
+    eq_ (type(u.to_unicode('hi')), six.text_type )
+    eq_ (type(u.to_unicode(u'hi')), six.text_type )
+    eq_ (type(u.to_unicode('привет')), six.text_type )
+    eq_ (type(u.to_unicode(u'привет')), six.text_type )
     eq_ (u"привет", u.to_unicode('привет'))
     eq_ (u"привет", u.to_unicode(u'привет'))
     # some latin1 stuff
-    eq_ (u"Versión", u.to_unicode('Versi\xf3n', precise=True))
+    eq_ (u"Versión", u.to_unicode(u'Versi\xf3n'.encode('iso-8859-2'), precise=True))
 
 
 def test_detect_encoding():
-    eq_ ('ascii', u.detect_encoding('qwe').lower())
-    eq_ ('iso-8859-2', u.detect_encoding('Versi\xf3n').lower())
-    eq_ ('utf-8', u.detect_encoding('привет').lower())
+    eq_ ('ascii', u.detect_encoding(b'qwe').lower())
+    eq_ ('iso-8859-2', u.detect_encoding(u'Versi\xf3n'.encode('iso-8859-2')).lower())
+    eq_ ('utf-8', u.detect_encoding(u'привет'.encode('utf8')).lower())
     # fallback to utf-8
     with patch.object(u.chardet, 'detect') as detect:
         detect.side_effect = Exception
-        eq_ ('utf-8', u.detect_encoding('qwe').lower())
+        eq_ ('utf-8', u.detect_encoding('qwe'.encode('utf8')).lower())
 
 
 def test_quick_detect_encoding():
-    eq_ ('ascii', u.quick_detect_encoding('qwe').lower())
-    eq_ ('windows-1252', u.quick_detect_encoding('Versi\xf3n').lower())
-    eq_ ('utf-8', u.quick_detect_encoding('привет').lower())
+    eq_ ('ascii', u.quick_detect_encoding(b'qwe').lower())
+    eq_ ('windows-1252', u.quick_detect_encoding(u'Versi\xf3n'.encode('windows-1252')).lower())
+    eq_ ('utf-8', u.quick_detect_encoding(u'привет'.encode('utf8')).lower())
 
 
 @patch.object(cchardet, 'detect')
 @patch.object(u, 'detect_encoding')
 def test_quick_detect_encoding_edge_cases(detect_encoding, cchardet_detect):
     cchardet_detect.return_value = {'encoding': 'ascii'}
-    eq_('ascii', u.quick_detect_encoding("qwe"))
-    cchardet_detect.assert_called_once_with("qwe")
+    eq_('ascii', u.quick_detect_encoding(b"qwe"))
+    cchardet_detect.assert_called_once_with(b"qwe")
 
     # fallback to detect_encoding
     cchardet_detect.return_value = {}
     detect_encoding.return_value = 'utf-8'
-    eq_('utf-8', u.quick_detect_encoding("qwe"))
+    eq_('utf-8', u.quick_detect_encoding(b"qwe"))
 
     # exception
     detect_encoding.reset_mock()
     cchardet_detect.side_effect = Exception()
     detect_encoding.return_value = 'utf-8'
-    eq_('utf-8', u.quick_detect_encoding("qwe"))
+    eq_('utf-8', u.quick_detect_encoding(b"qwe"))
     ok_(detect_encoding.called)
 
 
@@ -73,11 +75,11 @@ Haha
 </p>
 </body>"""
     text = u.html_to_text(html)
-    eq_("Hello world! \n\n  * One! \n  * Two \nHaha", text)
-    eq_("привет!", u.html_to_text("<b>привет!</b>"))
+    eq_(b"Hello world! \n\n  * One! \n  * Two \nHaha", text)
+    eq_(u"привет!", u.html_to_text("<b>привет!</b>").decode('utf8'))
 
     html = '<body><br/><br/>Hi</body>'
-    eq_ ('Hi', u.html_to_text(html))
+    eq_ (b'Hi', u.html_to_text(html))
 
     html = """Hi
 <style type="text/css">
@@ -97,11 +99,11 @@ font: 13px 'Lucida Grande', Arial, sans-serif;
 
 }
 </style>"""
-    eq_ ('Hi', u.html_to_text(html))
+    eq_ (b'Hi', u.html_to_text(html))
 
     html = """<div>
 <!-- COMMENT 1 -->
 <span>TEXT 1</span>
 <p>TEXT 2 <!-- COMMENT 2 --></p>
 </div>"""
-    eq_('TEXT 1 \nTEXT 2', u.html_to_text(html))
+    eq_(b'TEXT 1 \nTEXT 2', u.html_to_text(html))
diff --git a/train.py b/train.py
index 54d04b5..63ac7fa 100644
--- a/train.py
+++ b/train.py
@@ -1,3 +1,4 @@
+from __future__ import absolute_import
 from talon.signature import EXTRACTOR_FILENAME, EXTRACTOR_DATA
 from talon.signature.learning.classifier import train, init