Add Python < 3.3 support for pyabc.i

pyabc.i for abstract base classes now supports versions of Python
prior to 3.3 by using the collection module for these older versions.
Python-3.3 and later continue to use the collections.abc module.
The -py3 option no longer has any effect on the %pythonabc feature.

1 files changed, 12 insertions, 8 deletions

diff --git a/Lib/python/pyabc.i b/Lib/python/pyabc.i
index fbd91dce4..cae1e7032 100644
--- a/Lib/python/pyabc.i
+++ b/Lib/python/pyabc.i
@@ -1,10 +1,14 @@
 %define %pythonabc(Type, Abc)
-  %feature("python:abc", #Abc) Type;
+  %feature("python:abc", Abc) Type;
 %enddef
-%pythoncode %{import collections.abc%}
-%pythonabc(std::vector, collections.abc.MutableSequence);
-%pythonabc(std::list, collections.abc.MutableSequence);
-%pythonabc(std::map, collections.abc.MutableMapping);
-%pythonabc(std::multimap, collections.abc.MutableMapping);
-%pythonabc(std::set, collections.abc.MutableSet);
-%pythonabc(std::multiset, collections.abc.MutableSet);
+%pythoncode %{if _swig_python_version_info[0:2] >= (3, 3):
+    import collections.abc
+else:
+    import collections
+%}
+%pythonabc(std::vector, "collections.abc.MutableSequence if _swig_python_version_info >= (3, 3) else collections.MutableSequence");
+%pythonabc(std::list, "collections.abc.MutableSequence if _swig_python_version_info >= (3, 3) else collections.MutableSequence");
+%pythonabc(std::map, "collections.abc.MutableMapping if _swig_python_version_info >= (3, 3) else collections.MutableMapping");
+%pythonabc(std::multimap, "collections.abc.MutableMapping if _swig_python_version_info >= (3, 3) else collections.MutableMapping");
+%pythonabc(std::set, "collections.abc.MutableSet if _swig_python_version_info >= (3, 3) else collections.MutableSet");
+%pythonabc(std::multiset, "collections.abc.MutableSet if _swig_python_version_info >= (3, 3) else collections.MutableSet");