fix potential errors parsing the trailing month

Author: wenh06

bib_lookup/_bib.py

@@ -134,10 +134,13 @@ def __normalize_fields(self, check_fields: bool = False) -> None:
             # remove redundant curly braces and commas
             v = str(v).strip(" ,")  # DO NOT strip "{}"
             self.__double_braces_flags[k] = False
-            braces_count = 0
+            braces_count = 1
             # exclude the case where the leading and trailing words are enclosed by braces
             # e.g. "{IDH1} and {IDH2} mutations in postoperative diffuse glioma-associated {epilepsy}"
             tmp_v = re.sub("\\{[^\\{\\}]*\\}", "", v).strip()
+            if not re.findall("\\w+", tmp_v):
+                # exclude the case {{...}}
+                tmp_v = v
             while (
                 all([tmp_v.startswith("{"), tmp_v.endswith("}")])
                 or all([v.startswith('"'), v.endswith('"')])
@@ -146,6 +149,9 @@ def __normalize_fields(self, check_fields: bool = False) -> None:
                 v = v[1:-1]
                 braces_count += 1
                 tmp_v = re.sub("\\{[^\\{\\}]*\\}", "", v).strip()
+                if not re.findall("\\w+", tmp_v):
+                    # exclude the case {{...}}
+                    tmp_v = v
             if braces_count >= 2:
                 self.__double_braces_flags[k] = True
             # convert month to number if applicable

bib_lookup/bib_lookup.py

@@ -817,6 +817,10 @@ def _to_bib_item(
         field_dict = {k.lower(): v.strip(", ") for k, v in field_dict.items() if k.lower() not in _ignore_fields}
         # take off at most one pair of double quotes or single quotes or braces at the beginning and the end of the value
         for k, v in field_dict.items():
+            # if the field ends with a } but without a leading {, remove the trailing }
+            # this resolves the issue with fetched content that ends with, for example, "month=jun }"
+            if field_dict[k].endswith("}") and not field_dict[k].startswith("{"):
+                field_dict[k] = field_dict[k][:-1].strip()
             tmp_v = re.sub("\\{[^\\{\\}]*\\}", "", v).strip()
             if v.startswith('"') and v.endswith('"'):
                 field_dict[k] = v[1:-1]