Add XMLFormat.ns_prefix() convenience method

khaeru · Jul 31, 2023 · 8918f8f · 8918f8f
1 parent c3c94ee
commit 8918f8f
Showing 1 changed file with 8 additions and 0 deletions.
diff --git a/sdmx/format/xml/common.py b/sdmx/format/xml/common.py
@@ -84,6 +84,14 @@ def __eq__(self, other):
     def __hash__(self):
         return hash(self.base_ns)
 
+    @lru_cache()
+    def ns_prefix(self, url) -> str:
+        """Return the namespace prefix from :attr:`.NS` given its full `url`."""
+        for prefix, _url in self.NS.items():
+            if url == _url:
+                return prefix
+        raise ValueError(url)
+
     @lru_cache()
     def qname(self, ns_or_name, name=None) -> QName:
         """Return a fully-qualified tag `name` in namespace `ns`."""