FIX raises an error if a section appears twice

closes numpy#64

Author: NelleV

numpydoc/docscrape.py

@@ -323,10 +323,15 @@ def _parse(self):
             msg = 'Docstring contains both a Returns and Yields section.'
             raise ValueError(msg)
 
-        for (section, content) in sections:
+        for (section, content) in sections: 
             if not section.startswith('..'):
                 section = (s.capitalize() for s in section.split(' '))
                 section = ' '.join(section)
+                if self[section]:
+                    msg = ("The section %s appears twice in the docstring." %
+                           section)
+                    raise ValueError(msg)
+
             if section in ('Parameters', 'Returns', 'Yields', 'Raises',
                            'Warns', 'Other Parameters', 'Attributes',
                            'Methods'):

numpydoc/tests/test_docscrape.py

@@ -209,6 +209,22 @@ def test_returnyield():
 """
     assert_raises(ValueError, NumpyDocString, doc_text)
 
+
+def test_section_twice():
+    doc_text = """
+Test having a section Notes twice
+
+Notes
+-----
+See the next note for more information
+
+Notes
+-----
+That should break...
+"""
+    assert_raises(ValueError, NumpyDocString, doc_text)
+
+
 def test_notes():
     assert doc['Notes'][0].startswith('Instead')
     assert doc['Notes'][-1].endswith('definite.')