Return the resolved url

Author: alejandrogallo

src/doi/__init__.py

@@ -43,6 +43,8 @@ def validate_doi(doi):
 
     :param doi: Doi identificator
     :type  doi: str
+    :returns: It returns the url assigned to the doi if everything went right
+    :rtype: str
 
     :raises ValueError: Whenever the doi is not valid
     """
@@ -56,6 +58,10 @@ def validate_doi(doi):
 
     try:
         result = json.loads(urllib.request.urlopen(request).read().decode())
+        if 'values' in result:
+            url = [v['data']['value']
+                    for v in result['values'] if v.get('type') == 'URL']
+            return url[0] if url else None
     except HTTPError:
         raise ValueError('HTTP 404: DOI not found')
     except URLError as e:
@@ -117,3 +123,15 @@ def find_doi_in_text(text):
         except StopIteration:
             pass
     return None
+
+
+def get_real_url_from_doi(doi):
+    url = validate_doi(doi)
+    if not url:
+        return url
+
+    m = re.match('.*linkinghub\.elsevier.*/pii/([A-Z0-9]+).*', url, re.I)
+    if m:
+        return ('https://www.sciencedirect.com/science/article/abs/pii/{pii}'
+                .format(pii=m.group(1)))
+    return url

tests/test_doi.py

@@ -3,7 +3,10 @@
 import os
 from pkg_resources import parse_version
 
-from doi import validate_doi, find_doi_in_text, __version__, pdf_to_doi
+from doi import (
+    validate_doi, find_doi_in_text, __version__, pdf_to_doi,
+    get_real_url_from_doi
+)
 
 
 def test_valid_version():
@@ -12,14 +15,37 @@ def test_valid_version():
 
 
 def test_validate_doi():
-    doi = '10.1063/1.5081715'
-    validate_doi(doi)
+    data = [
+        ('10.1063/1.5081715',
+            'http://aip.scitation.org/doi/10.1063/1.5081715'),
+        ('10.1007%2FBF01451751',
+            'http://link.springer.com/10.1007/BF01451751'),
+        ('10.1103/PhysRevLett.49.57',
+            'https://link.aps.org/doi/10.1103/PhysRevLett.49.57'),
+        ('10.1080/14786442408634457',
+            'https://www.tandfonline.com/doi/full/10.1080/14786442408634457'),
+        ('10.1021/jp003647e', 'https://pubs.acs.org/doi/10.1021/jp003647e'),
+        ('10.1016/S0009-2614(97)04014-1',
+            'http://linkinghub.elsevier.com/retrieve/pii/S0009261497040141'),
+    ]
+    for doi, url in data:
+        assert(url == validate_doi(doi))
+
     for doi in ['', 'asdf']:
         try:
             validate_doi(doi)
         except ValueError as e:
             assert(str(e) == 'HTTP 404: DOI not found')
 
+def test_get_real_url_from_doi():
+    data = [
+        ('10.1016/S0009-2614(97)04014-1',
+         'https://www.sciencedirect.com/science/'
+         'article/abs/pii/S0009261497040141'),
+    ]
+    for doi, url in data:
+        assert(url == get_real_url_from_doi(doi))
+
 
 def test_find_doi_in_line():
     test_data = [