Return '' instead of None

pygnparser/utils/result.py

@@ -9,10 +9,10 @@ def _key(self, key, dict=None):
         if dict is None:
             dict = self.parsed_result
         try:
-            key = dict[key]
+            value = dict[key]
         except KeyError:
-            key = None
-        return key
+            value = ''
+        return value
 
 
     def parsed(self):
@@ -56,7 +56,7 @@ def page(self):
         if ':' in verbatim_authorship:
             page = verbatim_authorship.split(':')[-1].strip()
         else:
-            page = None
+            page = ''
         return page
 
 
@@ -82,7 +82,7 @@ def _format_authorship(self, authorship_details):
 
     def authorship(self):
         authorship_details = self.authorship_details()
-        authorship = None
+        authorship = ''
         if authorship_details is not None:
             if 'originalAuth' in authorship_details:
                 authorship = self._format_authorship(authorship_details['originalAuth'])
@@ -166,15 +166,15 @@ def infraspecies_details(self):
 
     def infraspecies(self):
         infraspecies_details = self.infraspecies_details()
-        if infraspecies_details is not None:
+        if infraspecies_details != '':
             return self._key('value', dict=infraspecies_details[0])
         else:
-            return None
+            return ''
 
 
     def infraspecies_rank(self):
         if self._details_rank() == 'infraspecies':
-            rank = None
+            rank = ''
             if self._key('rank', dict=self.details()[self._details_rank()]['infraspecies'][0]) is not None:
                 rank = self._key('rank', dict=self.details()[self._details_rank()]['infraspecies'][0])
         return rank

test/test-parse.py

@@ -120,7 +120,7 @@ def test_parse_infraspecies():
 @vcr.use_cassette("test/vcr_cassettes/test_parse_Aus_cus_dus.yaml")
 def test_parse_infraspecies_rank():
     res = gnparser('Aus (Bus) cus dus (Smith, 1980)')
-    assert res.infraspecies_rank() is None
+    assert res.infraspecies_rank() == ''
 
 
 @vcr.use_cassette("test/vcr_cassettes/test_parse_Aus_cus_var_dus.yaml")
@@ -259,7 +259,7 @@ def test_parse_Ablepharus_pannonicus():
     res = gnparser('Ablepharus pannonicus Fitzinger in Eversmann, 1823: 145 (Nom. Nud., In Error)')
     assert res.genus() == 'Ablepharus'
     assert res.species() == 'pannonicus'
-    assert res.infraspecies() is None
+    assert res.infraspecies() == ''
     assert res.authorship() == 'Fitzinger in Eversmann, 1823'
     assert res.page() == '145'
     assert res.quality_warnings() == [{'quality': 4, 'warning': 'Unparsed tail'}, {'quality': 2, 'warning': 'Ex authors are not required (ICZN only)'}, {'quality': 2, 'warning': 'Year with page info'}]
@@ -271,9 +271,9 @@ def test_parse_Aspidoscelis_neavesi():
     res = gnparser('Aspidoscelis neavesi Cole, Taylor, Baumann & Baumann, 2014 (Part)')
     assert res.genus() == 'Aspidoscelis'
     assert res.species() == 'neavesi'
-    assert res.infraspecies() is None
+    assert res.infraspecies() == ''
     assert res.authorship() == 'Cole, Taylor, Baumann & Baumann, 2014'
-    assert res.page() is None
+    assert res.page() == ''
     assert res.tail().strip() == '(Part)'
 
 
@@ -282,7 +282,7 @@ def test_parse_Atuechosaurus_travancoricus():
     res = gnparser('Atuechosaurus travancoricus Beddome, 1870: 33 (Part.)')
     assert res.genus() == 'Atuechosaurus'
     assert res.species() == 'travancoricus'
-    assert res.infraspecies() is None
+    assert res.infraspecies() == ''
     assert res.authorship() == 'Beddome, 1870'
     assert res.page() == '33'
     assert res.tail().strip() == '(Part.)'
@@ -293,7 +293,7 @@ def test_parse_Calyptoprymnus_verecundus():
     res = gnparser('Calyptoprymnus verecundus De Vis, 1905: 46 (Fide Moody, 1977)')
     assert res.genus() == 'Calyptoprymnus'
     assert res.species() == 'verecundus'
-    assert res.infraspecies() is None
+    assert res.infraspecies() == ''
     assert res.authorship() == 'De Vis, 1905'
     assert res.page() == '46'
     assert res.tail().strip() == '(Fide Moody, 1977)'