Add fallback to native etree implementation

.travis.yml

@@ -19,6 +19,7 @@ install:
     - if [[ $TRAVIS_PYTHON_VERSION != 'pypy'* && $DEPS == true ]]; then travis_retry pip install pycurl; fi
     - if [[ $TRAVIS_PYTHON_VERSION == '2.7' && $DEPS == true ]]; then travis_retry travis_retry pip install sphinx==1.2.2 sphinx_rtd_theme; fi
     - if [[ $TRAVIS_PYTHON_VERSION == '3.5' && $DEPS == true ]]; then travis_retry travis_retry pip install sphinx==1.2.2 sphinx_rtd_theme; fi
+    - if [[ $DEPS == true ]]; then travis_retry pip install lxml; fi
     - travis_retry python setup.py install
     - travis_retry pip install pep8 coverage==3.7.1 codecov coveralls pycurl pycares
 

setup.py

@@ -43,7 +43,7 @@ def run(self):
         with open(os.path.join(build_dir, 'version.py'), 'w') as version_file:
             version_file.write('version = "{0}"\n'.format(version))
 
-install_requires = ['tornado', 'lxml', 'jinja2', 'six']
+install_requires = ['tornado', 'jinja2', 'six']
 
 setup(
     name="tortik",

tortik/page/__init__.py

@@ -16,18 +16,17 @@
 except ImportError:
     import urllib.parse as urlparse  # py3
 
-import lxml.etree as etree
 import tornado.web
 import tornado.httpclient
 from tornado.options import options, define
 from tornado.escape import to_unicode
 import tornado.gen
-from tornado.util import unicode_type
 from jinja2 import Environment, PackageLoader
 import six
 
 from tortik.util import decorate_all, make_list, real_ip, make_qs
 from tortik.util.dumper import dump
+from tortik.util.xml_etree import tostring
 from tortik.logger import PageLogger
 from tortik.util.async import AsyncGroup
 from tortik.util.parse import parse_xml, parse_json
@@ -162,7 +161,7 @@ def finish_with_debug(self):
             size=sys.getsizeof,
             get_params=lambda x: urlparse.parse_qs(x, keep_blank_values=True),
             pretty_json=lambda x: json.dumps(x, sort_keys=True, indent=4, ensure_ascii=False),
-            pretty_xml=lambda x: etree.tostring(x, pretty_print=True, encoding=unicode_type),
+            pretty_xml=lambda x: to_unicode(tostring(x, pretty_print=True, encoding='UTF-8')),
             to_unicode=to_unicode,
             dumper=dump,
             format_exception=lambda x: "".join(traceback.format_exception(*x))

tortik/util/parse.py

@@ -1,8 +1,8 @@
 # -*- coding: utf-8 -*-
-from lxml import etree
 from tornado.escape import json_decode
 
 from tortik.util import HTTPError
+from tortik.util.xml_etree import parse, ParseError
 
 try:
     import httplib  # py2
@@ -14,9 +14,8 @@ def parse_xml(response):
     if response.code == 599 or response.buffer is None:
         raise HTTPError(httplib.SERVICE_UNAVAILABLE, 'Response timeout or no body buffer')
     try:
-        parser = etree.XMLParser(remove_blank_text=True)
-        return etree.parse(response.buffer, parser=parser)
-    except etree.ParseError:
+        return parse(response.buffer)
+    except ParseError:
         raise HTTPError(httplib.SERVICE_UNAVAILABLE, 'Unable to parse xml')
 
 

tortik/util/xml_etree.py

@@ -0,0 +1,34 @@
+# -*- coding: utf-8 -*-
+from tortik.logger import tortik_log
+
+native_etree = False
+
+try:
+    from lxml import etree
+except ImportError:
+    tortik_log.info('lxml not installed. Using native etree implementation')
+    native_etree = True
+    import xml.etree.ElementTree as etree
+
+
+def parse(source, parser=None):
+    if parser is None and native_etree is False:
+        parser = etree.XMLParser(remove_blank_text=True)
+
+    return etree.parse(source, parser)
+
+
+def tostring(element, **kwargs):
+    native_args = ['encoding', 'method']
+    if native_etree is True:
+        pass_args = dict()
+        for a in native_args:
+            if a in kwargs:
+                pass_args[a] = kwargs[a]
+    else:
+        pass_args = kwargs
+
+    return etree.tostring(element, **pass_args)
+
+
+ParseError = etree.ParseError

tortik_tests/util_test.py

@@ -1,9 +1,16 @@
 # _*_ coding: utf-8 _*_
 
+try:
+    from cStringIO import StringIO  # python 2
+except ImportError:
+    from io import StringIO  # python 3
+
 from collections import OrderedDict
 import unittest
+from tornado.escape import to_unicode
 
 from tortik.util import make_qs, update_url
+from tortik.util.xml_etree import parse, tostring
 
 
 class BaseTest(unittest.TestCase):
@@ -96,3 +103,35 @@ def test_both(self):
                              'http://google.com?a=1')
         self.assertUrlsEqual(update_url('http://google.com?a=2&b=3&c=4', update_args={'a': 1}, remove_args=['b']),
                              'http://google.com?a=1&c=4')
+
+
+class TestParse(BaseTest):
+    def test_parse_xml(self):
+        mock_xml = b'''<?xml version="1.0" encoding="UTF-8"?>
+<data>
+    <country name="Liechtenstein">
+        <rank>1</rank>
+        <year>2008</year>
+        <gdppc>141100</gdppc>
+        <neighbor name="Austria"/>
+        <neighbor name="Switzerland"/>
+    </country>
+    <country name="Singapore">
+        <rank>4</rank>
+        <year>2011</year>
+        <gdppc>59900</gdppc>
+        <neighbor name="Malaysia"/>
+    </country>
+    <country name="Panama">
+        <rank>68</rank>
+        <year>2011</year>
+        <gdppc>13600</gdppc>
+        <neighbor name="Costa Rica"/>
+        <neighbor name="Colombia"/>
+    </country>
+</data>'''
+        tree = parse(StringIO(to_unicode(mock_xml)))
+        self.assertEqual(tree.getroot().tag, 'data')
+        convert = tostring(tree.getroot(), pretty_print=True, xml_declaration=True, encoding='UTF-8')
+        self.assertEqual(to_unicode(convert).replace('\n', '').replace(' ', '').replace('\'', '"').strip(),
+                         to_unicode(mock_xml).replace('\n', '').replace(' ', '').strip())