#119 Requested changes: Clean up the elif convolute

pubmed_parser/pubmed_oa_parser.py

@@ -235,6 +235,15 @@ def parse_pubmed_xml(path, include_path=False, nxml=False):
     return dict_out
 
 
+def get_reference(reference):
+    """Get reference from one of the three possible positions."""
+    for tag in ["mixed-citation", "element-citation", "citation"]:
+        ref = reference.find(tag)
+        if ref is not None:
+            return ref
+    return None
+
+
 def parse_pubmed_references(path):
     """
     Given path to xml file, parse references articles
@@ -260,15 +269,7 @@ def parse_pubmed_references(path):
     for reference in references:
         ref_id = reference.attrib["id"]
 
-        if reference.find("mixed-citation") is not None:
-            ref = reference.find("mixed-citation")
-        elif reference.find("element-citation") is not None:
-            ref = reference.find("element-citation")
-        elif reference.find("citation") is not None:
-            ref = reference.find("citation")
-        else:
-            ref = None
-
+        ref = get_reference(reference)
         if ref is not None:
             ref_types = ["citation-type", "publication-type"]
             if any(ref_type in ref_types for ref_type in ref.attrib.keys()):