WIP: Feature/impr c fallback

tests/test_c_fallback.py

@@ -0,0 +1,10 @@
+"""Test that the C version fallback/fail works for PyYAML cyaml."""
+from __future__ import print_function, division, absolute_import
+
+from unittest import TestCase
+
+
+class TestCVersionHandling(TestCase):
+
+    def test_c_fallback(self):
+        import yamlloader

yamlloader/ordereddict/__init__.py

@@ -2,14 +2,23 @@
 """YAML loaders and dumpers for PyYAML allowing to keep keys order."""
 from __future__ import print_function, division, absolute_import
 
-from .loaders import Loader, SafeLoader, CLoader, CSafeLoader
-from .dumpers import Dumper, SafeDumper, CDumper, CSafeDumper
+from .loaders import Loader, SafeLoader
+from .dumpers import Dumper, SafeDumper
 
-__all__ = ['CLoader',
-           'Loader',
-           'CDumper',
+__c_handler_names = []
+
+try:
+    from .loaders import CLoader, CSafeLoader
+    from .dumpers import CDumper, CSafeDumper
+    __c_handler_names += ['CLoader',
+                          'CDumper',
+                          'CSafeLoader',
+                          'CSafeDumper',
+                          ]
+except ImportError:  # PyYAML.cyaml not available -> error
+    pass  # C version not available
+
+__all__ = ['Loader',
            'Dumper',
-           'CSafeLoader',
            'SafeLoader',
-           'CSafeDumper',
-           'SafeDumper']
+           'SafeDumper'] + __c_handler_names

yamlloader/ordereddict/dumpers.py

@@ -20,7 +20,7 @@ def __init__(self, *args, **kwargs):
         sub_doc = self.__doc__
         if sub_doc is None:
             sub_doc = ""
-        self.__doc__ = """Dump `:py:class:~collections.OrderedDict` to YAML preserving the order."""
+        self.__doc__ = """Dump :py:class:`~collections.OrderedDict` to YAML preserving the order."""
         self.__doc__ += sub_doc
         super(OrderedDumperMixin, self).__init__(*args, **kwargs)
         self.add_representer(OrderedDict, type(self).represent_ordereddict)
@@ -44,17 +44,17 @@ class SafeDumper(OrderedDumperMixin, yaml.SafeDumper):
     """
 
 
-if not hasattr(yaml, 'CDumper') and yamlloader.settings.ALLOW_NON_C_FALLBACK:
-    yaml.CDumper = yaml.Dumper
+if not hasattr(yaml, 'CDumper'):
+    if yamlloader.settings.ALLOW_NON_C_FALLBACK:
+        CDumper = Dumper
+else:
+    class CDumper(OrderedDumperMixin, yaml.CDumper):
+        __doc__ = doc_extension_Cversion
 
 
-
-class CDumper(OrderedDumperMixin, yaml.CDumper):
-    __doc__ = doc_extension_Cversion
-
-
-if not hasattr(yaml, 'CSafeDumper') and yamlloader.settings.ALLOW_NON_C_FALLBACK:
-    yaml.CSafeDumper = yaml.SafeDumper
-
-class CSafeDumper(OrderedDumperMixin, yaml.CSafeDumper):
-    __doc__ = doc_extension_Cversion
+if not hasattr(yaml, 'CSafeDumper'):
+    if yamlloader.settings.ALLOW_NON_C_FALLBACK:
+        CSafeDumper = SafeDumper
+else:
+    class CSafeDumper(OrderedDumperMixin, yaml.CSafeDumper):
+        __doc__ = doc_extension_Cversion

yamlloader/ordereddict/loaders.py

@@ -58,17 +58,17 @@ class SafeLoader(OrderedLoaderMixin, yaml.SafeLoader):
     pass
 
 
-if not hasattr(yaml, 'CLoader') and yamlloader.settings.ALLOW_NON_C_FALLBACK:
-    yaml.CLoader = yaml.Loader
-
-
-class CLoader(OrderedLoaderMixin, yaml.CLoader):
-    pass
-
-
-if not hasattr(yaml, 'CSafeLoader') and yamlloader.settings.ALLOW_NON_C_FALLBACK:
-    yaml.CSafeLoader = yaml.SafeLoader
-
-
-class CSafeLoader(OrderedLoaderMixin, yaml.CSafeLoader):
-    pass
+if not hasattr(yaml, 'CLoader'):
+    if yamlloader.settings.ALLOW_NON_C_FALLBACK:
+        CLoader = Loader
+else:
+    class CLoader(OrderedLoaderMixin, yaml.CLoader):
+        pass
+
+
+if not hasattr(yaml, 'CSafeLoader'):
+    if yamlloader.settings.ALLOW_NON_C_FALLBACK:
+        CSafeLoader = SafeLoader
+else:
+    class CSafeLoader(OrderedLoaderMixin, yaml.CSafeLoader):
+        pass