From 100b2a5e6c6e8f1e407875e6e2b74d9c60b77ff0 Mon Sep 17 00:00:00 2001
From: "Gerber, Mike" <mike.gerber@sbb.spk-berlin.de>
Date: Mon, 17 Apr 2023 19:21:43 +0200
Subject: [PATCH] =?UTF-8?q?=F0=9F=90=9B=20=20Fix=20mods:relatedItem=20with?=
 =?UTF-8?q?=20mods:recordIdentifier=20source=3Ddnb-ppn?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

mods:relatedItem may have a mods:recordIdentifier with source="dnb-ppn".
This may happen for digitized works that have their original work in
another library and use a DNB PPN there.

Fixes gh-22.
---
 qurator/mods4pandas/mods4pandas.py         |  8 +++++++-
 qurator/mods4pandas/tests/test_modstool.py | 13 +++++++++++++
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/qurator/mods4pandas/mods4pandas.py b/qurator/mods4pandas/mods4pandas.py
index 781c42c..45fb675 100755
--- a/qurator/mods4pandas/mods4pandas.py
+++ b/qurator/mods4pandas/mods4pandas.py
@@ -95,7 +95,13 @@ def mods_to_dict(mods, raise_errors=True):
         elif tag == '{http://www.loc.gov/mods/v3}recordInfo':
             value['recordInfo'] = TagGroup(tag, group).is_singleton().has_no_attributes().descend(raise_errors)
         elif tag == '{http://www.loc.gov/mods/v3}recordIdentifier':
-            value['recordIdentifier'] = TagGroup(tag, group).is_singleton().has_attributes({'source': 'gbv-ppn'}).text()
+            # By default we assume source="gbv-ppn" mods:recordIdentifiers (= PPNs),
+            # however, in mods:relatedItems, there may be source="dnb-ppns",
+            # which we need to distinguish by using a separate field name.
+            try:
+                value['recordIdentifier'] = TagGroup(tag, group).is_singleton().has_attributes({'source': 'gbv-ppn'}).text()
+            except ValueError:
+                value['recordIdentifier-dnb-ppn'] = TagGroup(tag, group).is_singleton().has_attributes({'source': 'dnb-ppn'}).text()
         elif tag == '{http://www.loc.gov/mods/v3}identifier':
             for e in group:
                 if len(e.attrib) != 1:
diff --git a/qurator/mods4pandas/tests/test_modstool.py b/qurator/mods4pandas/tests/test_modstool.py
index 5d628a2..3fb6460 100644
--- a/qurator/mods4pandas/tests/test_modstool.py
+++ b/qurator/mods4pandas/tests/test_modstool.py
@@ -138,3 +138,16 @@ def test_relatedItem():
     """)
 
     assert d['relatedItem-original_recordInfo_recordIdentifier'] == 'PPN167755803'
+
+    # mods:relatedItem may also have source="dnb-ppn" recordIdentifiers:
+    d = dict_fromstring("""
+    <mods:mods xmlns:mods="http://www.loc.gov/mods/v3">
+        <mods:relatedItem type="original">
+            <mods:recordInfo>
+                <mods:recordIdentifier source="dnb-ppn">1236513355</mods:recordIdentifier>
+            </mods:recordInfo>
+        </mods:relatedItem>
+    </mods:mods>
+    """)
+
+    assert d['relatedItem-original_recordInfo_recordIdentifier-dnb-ppn'] == '1236513355'