python 3.4 compatibility

ippisite/ippidb/ws.py

@@ -169,7 +169,7 @@ def get_doi_info(doi):
     :return: publication metadata (title, journal name, publication year, authors list).
     :rtype: dict
     """
-    resp = requests.get(f'http://dx.doi.org/{doi}', headers={'Accept':'application/vnd.citationstyles.csl+json'})
+    resp = requests.get('http://dx.doi.org/%s' % doi, headers={'Accept':'application/vnd.citationstyles.csl+json'})
     resp.raise_for_status()
     json_data = resp.json()
     title = json_data['title']
@@ -185,18 +185,18 @@ def get_doi_info(doi):
         else:
             biblio_year = json_data['published-online']['date-parts'][0][0]
     except KeyError as e:
-        print(f'http://dx.doi.org/{doi}')
+        print('http://dx.doi.org/%s' % doi)
         print(json_data)
         raise e
     authors_list = []
     for author_data in json_data['author']:
         try:
             if 'family' in author_data:
-                authors_list.append(f'{author_data["family"]} {author_data.get("given","")}')
+                authors_list.append('%s %s' % (author_data["family"], author_data.get("given", "")))
             else:
                 authors_list.append(author_data['name'])
         except KeyError as e:
-            print(f'http://dx.doi.org/{doi}')
+            print('http://dx.doi.org/%s' % doi)
             print(json_data)
             raise e
     authors = ', '.join(authors_list)