New example: nested.cpp

[SVN r10946]

example/nested.cpp

@@ -0,0 +1,44 @@
+// Example by Ralf W. Grosse-Kunstleve
+
+/*
+    This example shows how convert a nested Python tuple.
+ */
+
+#include <boost/python/class_builder.hpp>
+#include <stdio.h>
+
+namespace {
+
+  boost::python::list
+  show_nested_tuples(boost::python::tuple outer)
+  {
+    boost::python::list result;
+    for (int i = 0; i < outer.size(); i++) {
+      boost::python::tuple inner(
+        BOOST_PYTHON_CONVERSION::from_python(outer[i].get(),
+        boost::python::type<boost::python::tuple>()));
+      for (int j = 0; j < inner.size(); j++) {
+        double x = BOOST_PYTHON_CONVERSION::from_python(inner[j].get(),
+          boost::python::type<double>());
+        char buf[128];
+        sprintf(buf, "(%d,%d) %.6g", i, j, x);
+        result.append(BOOST_PYTHON_CONVERSION::to_python(std::string(buf)));
+      }
+    }
+    return result;
+  }
+
+}
+
+BOOST_PYTHON_MODULE_INIT(nested)
+{
+  try
+  {
+    boost::python::module_builder this_module("nested");
+    this_module.def(show_nested_tuples, "show_nested_tuples");
+  }
+  catch(...)
+  {
+    boost::python::handle_exception();
+  }
+}

example/test_nested.py

@@ -0,0 +1,23 @@
+r'''>>> import nested
+    >>> s = nested.show_nested_tuples(((1,2,3), (4,5,6,7)))
+    >>> for l in s:
+    ...   print l
+    (0,0) 1
+    (0,1) 2
+    (0,2) 3
+    (1,0) 4
+    (1,1) 5
+    (1,2) 6
+    (1,3) 7
+'''
+
+def run(args = None):
+    if args is not None:
+        import sys
+        sys.argv = args
+    import doctest, test_nested
+    return doctest.testmod(test_nested)
+
+if __name__ == '__main__':
+    import sys
+    sys.exit(run()[0])