From 5f79200722d707d406ded1b5afe1ea4951aba332 Mon Sep 17 00:00:00 2001
From: Tobias Zimmermann <77075037+tZimmermann98@users.noreply.github.com>
Date: Mon, 3 Feb 2025 11:52:05 +0100
Subject: [PATCH] fallback to regex year extraction or empty String when arrow
 fails

---
 scholarly/publication_parser.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/scholarly/publication_parser.py b/scholarly/publication_parser.py
index 50ff1e4..297360a 100644
--- a/scholarly/publication_parser.py
+++ b/scholarly/publication_parser.py
@@ -316,7 +316,8 @@ def fill(self, publication: Publication)->Publication:
                         publication['bib']['pub_year'] = arrow.get(val.text, patterns).year
                     except ValueError:
                         # fallback to regex year extraction if arrow fails
-                         publication['bib']['pub_year'] = re.search(r'\d{4}', val.text).group()
+                        match = re.search(r'\d{4}', val.text)
+                        publication['bib']['pub_year'] = match.group() if match else ""
                     publication['bib']['pub_date'] = val.text
                 elif key == 'description':
                     # try to find all the gsh_csp if they exist