Merge pull request #20 from dwieeb/master

Fix for #17

3 files changed, 12 insertions, 10 deletions

diff --git a/tests/test_from_fixtures.py b/tests/test_from_fixtures.py
index 0c23cc3..0ecc075 100644
--- a/tests/test_from_fixtures.py
+++ b/tests/test_from_fixtures.py
@@ -102,7 +102,8 @@ class TestSpecExamplesByRFCSection(FixtureMixin):
 class TestExtendedTests(FixtureMixin):
     examples = load_examples('extended-tests')
 
-    @pytest.mark.xfail(reason='See bug #17')
+    @pytest.mark.xfail(sys.version_info < (3, 0),
+                       reason='See bug #19')
     def test_additional_examples_1(self):
         """Check Additional Examples 1."""
         self._test('Additional Examples 1')
diff --git a/tox.ini b/tox.ini
index e15543c..b81521a 100644
--- a/tox.ini
+++ b/tox.ini
@@ -11,7 +11,7 @@ envlist =
 [testenv]
 deps =
     pytest
-commands = py.test
+commands = py.test {posargs}
 
 [testenv:pep8]
 deps =
diff --git a/uritemplate/variable.py b/uritemplate/variable.py
index a17c2e1..2f6dbd9 100644
--- a/uritemplate/variable.py
+++ b/uritemplate/variable.py
@@ -137,13 +137,15 @@ class URIVariable(object):
 
     def _query_expansion(self, name, value, explode, prefix):
         """Expansion method for the '?' and '&' operators."""
-        if value is None or (len(value) == 0 and value != ""):
+        if value is None:
             return None
 
         tuples, items = is_list_of_tuples(value)
 
         safe = self.safe
         if list_test(value) and not tuples:
+            if not value:
+                return None
             if explode:
                 return self.join_str.join(
                     '%s=%s' % (name, quote(v, safe)) for v in value
@@ -153,6 +155,8 @@ class URIVariable(object):
                 return '%s=%s' % (name, value)
 
         if dict_test(value) or tuples:
+            if not value:
+                return None
             items = items or sorted(value.items())
             if explode:
                 return self.join_str.join(
@@ -170,7 +174,7 @@ class URIVariable(object):
 
         if value:
             value = value[:prefix] if prefix else value
-            return '%s=%s' % (name, quote(value, safe))
+            return '%s=%s' % (name, quote(str(value), safe))
         return name + '='
 
     def _label_path_expansion(self, name, value, explode, prefix):
@@ -342,14 +346,11 @@ class URIVariable(object):
 
 
 def is_list_of_tuples(value):
-    if not isinstance(value, (list, tuple)):
+    if not value or not isinstance(value, (list, tuple)) or \
+            not all(isinstance(t, tuple) and len(t) == 2 for t in value):
         return False, None
 
-    try:
-        dict(value)
-        return True, value
-    except:
-        return False, None
+    return True, value
 
 
 def list_test(value):