refactor and fix accessing empty string error in parsing authors ID f…

…ield

litstudy/sources/scopus_csv.py

@@ -42,103 +42,111 @@ def __init__(self, entry):
 
     @property
     def title(self) -> Optional[str]:
-        return self.entry.get("Title") or None
+        return self.entry.get("Title")
 
-    def _get_authors(self) -> Optional[List[str]]:
+    def _parse_authors(self, auths: str) -> List[str]:
         """
         helper method. parse two formats of Authors field.
         Formats:
-            1. deliminates author by , and [No author name available]
-            2. deliminates author by ; and [No Authors found]
-        """
-        auths = self.entry.get("Authors")
-        no_authors_formats = ["[No Authors Found]", "[No author name available]"]
 
-        if auths in no_authors_formats:
-            return []
+            1. deliminated by , or ;
 
+        if either deliminator isn't present, will assume
+        only one author in field
+        """
         if ";" in auths:
             author_list = auths.split("; ")
         elif "," in auths:
             author_list = auths.split(", ")
             # add comma between auth last, first to match format
             # in authors with affiliations
-            author_list = [', '.join(auth.rsplit(" ", 1)) for auth in author_list]
-        else: # single author...
-            author_list = [auths]
+            author_list = [", ".join(auth.rsplit(" ", 1)) for auth in author_list]
 
+        else:  # single author...
+            author_list = [auths]
         return author_list
 
-    def _get_authors_ids(self) -> Optional[List[str]]:
+    def _get_authors_ids(self) -> List[str]:
         """
         helper method to parse two formats of
             'Author(s) ID' field
+
         1. AUTHOR_ID;AUTHOR_ID_2;LAST_AUTHOR_ID;
         2. AUTHOR_ID; AUTHOR_ID_2; LAST AUTHOR_ID
         """
-        auths_id = self.entry.get("Author(s) ID", "")
+        auths_id = self.entry.get("Author(s) ID")
+
+        if auths_id == "":
+            return []
+
         if auths_id[-1] == ";":
             auths_id = auths_id[:-1]
+
         auths_ids = auths_id.split(";")
         auths_ids = [auth_id.lstrip().rstrip() for auth_id in auths_ids]
         return auths_ids
 
-    def _get_auths_with_ids(self):
-        auths = self._get_authors()
-        auths_id = self._get_authors_ids()
+    def _try_to_add_ids_to_authors(self, auths: List[str]) -> List[str]:
+        """
+        auths is non-zero length list.
+        """
+        auths_ids = self._get_authors_ids()
 
-        if len(auths) == len(auths_id):
-            auths_w_ids = [f"{name} (ID: {auth_id})" for name, auth_id in zip(auths, auths_id)]
-        else:
-            auths_w_ids = []
-        return auths_w_ids
+        if len(auths_ids) == len(auths) and len(auths) > 0:
+            auths_w_ids = [f"{name} (ID: {auth_id})" for name, auth_id in zip(auths, auths_ids)]
+            return auths_w_ids
+        return auths
 
-    @staticmethod
-    def _get_affiliations(affiliation_substring):
-        affiliations = affiliation_substring.split(";")
-        affiliations = [
-            ScopusCsvAffiliation(aff) for aff in affiliations]
-        return affiliations
+    def _parse_affiliations(self, affs) -> List[str]:
+        if affs == "":
+            return []
+        return affs.split(";")
 
     @property
     def authors(self) -> List[ScopusCsvAuthor]:
-        auths = self._get_authors()
-        auths_affs = self.entry.get("Authors with affiliations")
-        auths_ids = self._get_authors_ids()
-        affs = self.entry.get("Affiliations")
-        # author_last, first initial, affiliation; .....
-        # try to add id to author name
-        if not auths_affs or auths is None or auths_ids is None:
+        auths = self.entry.get("Authors")
+        no_authors_formats = ["[No Authors Found]", "[No author name available]"]
+
+        if auths == "" or auths in no_authors_formats:
             return []
 
-        auths_w_ids = self._get_auths_with_ids()
+        # use auths to search in auths_with_affs string
+        auths = self._parse_authors(auths)
+        authors_with_ids = self._try_to_add_ids_to_authors(auths)
+
+        affs = self.entry.get("Affiliations")
+        affs = self._parse_affiliations(affs)
         # if single author, no way to know if ',' in author name
-        # within auths_affs field,
-        # so need to use 'Affiliations' field instead
-        # of searching for author in auths_affs
+        # within auths_affs field (can't search string),
+        # use 'Affiliations' field.
+
         if len(auths) == 1:
-            return [ScopusCsvAuthor(auths[0], self._get_affiliations(affs))]
+            return [
+                ScopusCsvAuthor(authors_with_ids[0], [ScopusCsvAffiliation(aff) for aff in affs])
+            ]
+
+        auths_affs = self.entry.get("Authors with affiliations")
+        if auths_affs == "":  # can't map affiliations to authors
+            return [ScopusCsvAuthor(auth, []) for auth in authors_with_ids]
+
         indexes_of_authors = [auths_affs.index(auth) for auth in auths]
         auth_to_affs_mapping = {}
+
         for num, index in enumerate(indexes_of_authors):
-            auth = auths[num]
-            if num < len(indexes_of_authors) - 1:
+            #auth = auths[num]
 
-                next_index = indexes_of_authors[num+1]
-                substring = auths_affs[index:next_index]
-                # only want part of string for current auhtor
+            if num < len(indexes_of_authors) - 1:
+                next_index = indexes_of_authors[num + 1]
+                cur_auth_affils = auths_affs[index:next_index]
+                # only want part of string for current author
                 # and affiliations
             else:
-                substring = auths_affs[index:]
-
-            substring = substring.replace(f"{auth}, ", "")
-            affiliations = substring.split(";")
-            affiliations = [
-                ScopusCsvAffiliation(aff) for aff in affiliations]
-            if auths_w_ids!=[]:
-                auth_to_affs_mapping[auths_w_ids[num]] = affiliations
-            else:
-                auth_to_affs_mapping[auth] = affiliations
+                cur_auth_affils = auths_affs[index:]
+
+            # cur_auth_affils = substring.replace(f"{auth}, ", "")
+            # could be multiple affiliates, but no clear deliminator
+            cur_auth_affils = [ScopusCsvAffiliation(a) for a in affs if a in cur_auth_affils]
+            auth_to_affs_mapping[authors_with_ids[num]] = cur_auth_affils
 
         return [ScopusCsvAuthor(a, b) for a, b in auth_to_affs_mapping.items()]