IMPR: use items() to iterate over bib_source dictionary

Change-Id: I5a6d1fe2da991a996ee5708713e04248192403b0
---
M scripts/create_isbn_edition.py
1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/scripts/create_isbn_edition.py b/scripts/create_isbn_edition.py
index c435a54..a042a99 100755
--- a/scripts/create_isbn_edition.py
+++ b/scripts/create_isbn_edition.py
@@ -1596,10 +1596,9 @@
         mainlang = bib_source[booklib][2]
     else:
         # Unknown bib reference - show implemented codes
-        for seq in bib_source:
+        for seq, ref in bib_source.items():
             pywikibot.info(
-                f'{seq.ljust(10)}{bib_source[seq][2].ljust(4)}'
-                f'{bib_source[seq][3].ljust(20)}{bib_source[seq][1]}'
+                f'{seq.ljust(10)}{ref[2].ljust(4)}{ref[3].ljust(20)}{ref[1]}'
             )
         fatal_error(3, f'Unknown Digital library ({REFPROP}) {booklib}')
 

