xml.etree: Fix namespace prefix resolution in ElementPath xpath_tokenizer (GH-140123)

The namespace prefix resolution in ElementPath.xpath_tokenizer now properly uses globally
registered namespaces after trying local namespaces first. This ensures consistent namespace
handling across both Python and C implementations.

Author: sangampaudel530

Lib/xml/etree/ElementPath.py

@@ -18,6 +18,8 @@
 #
 # [email protected]
 # http://www.pythonware.com
+
+from . import ElementTree
 #
 # --------------------------------------------------------------------
 # The ElementTree toolkit is
@@ -79,11 +81,14 @@ def xpath_tokenizer(pattern, namespaces=None):
         if tag and tag[0] != "{":
             if ":" in tag:
                 prefix, uri = tag.split(":", 1)
-                try:
-                    if not namespaces:
-                        raise KeyError
+                if namespaces and prefix in namespaces:
+                    # Use the passed-in namespace map first
                     yield ttype, "{%s}%s" % (namespaces[prefix], uri)
-                except KeyError:
+                elif prefix in ElementTree._namespace_map:
+                    # Then check the global registry
+                    yield ttype, "{%s}%s" % (ElementTree._namespace_map[prefix], uri)
+                else:
+                    # No namespace found, raise error
                     raise SyntaxError("prefix %r not found in prefix map" % prefix) from None
             elif default_namespace and not parsing_attribute:
                 yield ttype, "{%s}%s" % (default_namespace, tag)

Misc/NEWS.d/next/Library/2023-10-20-14-30-00.gh-issue-140123.rst

@@ -0,0 +1 @@
+ElementTree.find() and similar methods now properly use globally registered namespaces when resolving namespace prefixes in XPath expressions.