Don't chain exceptions raising in decimal binary loading

diff --git a/psycopg3/psycopg3/types/numeric.py b/psycopg3/psycopg3/types/numeric.py
index 0108e95aafeab4b474b473ed4bb8d41773ceabbe..d1dca439f5670a5bb48254ea39aec511bf8af3d7 100644 (file)
--- a/psycopg3/psycopg3/types/numeric.py
+++ b/psycopg3/psycopg3/types/numeric.py
@@ -369,7 +369,9 @@ class NumericBinaryLoader(Loader):
             try:
                 return _decimal_special[sign]
             except KeyError:
-                raise e.DataError(f"bad value for numeric sign: 0x{sign:X}")
+                raise e.DataError(
+                    f"bad value for numeric sign: 0x{sign:X}"
+                ) from None
 
 
 NUMERIC_NAN_BIN = _pack_numeric_head(0, 0, NUMERIC_NAN, 0)