Set format_checker to None for draft3 and 4

Author: manycoding

jsonschema/validators.py

@@ -29,8 +29,6 @@
 )
 
 from jsonschema._format import (
-    draft3_format_checker,
-    draft4_format_checker,
     draft6_format_checker,
     draft7_format_checker,
 )
@@ -443,7 +441,7 @@ def extend(validator, validators=(), version=None, type_checker=None):
     type_checker=_types.draft3_type_checker,
     version="draft3",
     id_of=lambda schema: schema.get(u"id", ""),
-    format_checker=draft3_format_checker,
+    format_checker=None,
 )
 
 Draft4Validator = create(
@@ -479,7 +477,7 @@ def extend(validator, validators=(), version=None, type_checker=None):
     type_checker=_types.draft4_type_checker,
     version="draft4",
     id_of=lambda schema: schema.get(u"id", ""),
-    format_checker=draft4_format_checker,
+    format_checker=None,
 )
 
 Draft6Validator = create(