Fix using named param more than once

Author: Kareem Zidane

src/cs50/_statement.py

@@ -197,18 +197,21 @@ def _substitute_named_or_pyformat_markers(self):
         Raises a ``RuntimeError`` if any parameters are missing or unused.
         """
 
-        unused_params = set(self._kwargs.keys())
+        unused_params = {param_name: True for param_name in self._kwargs.keys()}
         for token_index, param_name in self._placeholders.items():
             if param_name not in self._kwargs:
                 raise RuntimeError(f"missing value for placeholder ({param_name})")
 
             self._tokens[token_index] = self._kwargs[param_name]
-            unused_params.remove(param_name)
+            unused_params[param_name] = False
 
-        if len(unused_params) > 0:
-            joined_unused_params = get_human_readable_list(sorted(unused_params))
+        sorted_unique_unused_param_names = sorted(set(
+            param_name for param_name, unused in unused_params.items() if unused))
+        if len(sorted_unique_unused_param_names) > 0:
+            joined_unused_params = get_human_readable_list(sorted_unique_unused_param_names)
             raise RuntimeError(
-                f"unused value{'' if len(unused_params) == 1 else 's'} ({joined_unused_params})")
+                f"unused value{'' if len(sorted_unique_unused_param_names) == 1 else 's'}"
+                + " ({joined_unused_params})")
 
     def _escape_verbatim_colons(self):
         """Escapes verbatim colons from string literal and identifier tokens so they aren't treated

tests/sql.py

@@ -223,6 +223,10 @@ def test_named(self):
         self.assertEqual(self.db.execute("SELECT * FROM foo"), [{"firstname": "bar", "lastname": "baz"}])
         self.db.execute("DELETE FROM foo")
 
+        self.db.execute("INSERT INTO foo VALUES (:baz, :baz)", baz="baz")
+        self.assertEqual(self.db.execute("SELECT * FROM foo"), [{"firstname": "baz", "lastname": "baz"}])
+        self.db.execute("DELETE FROM foo")
+
         self.db.execute("CREATE TABLE bar (firstname VARCHAR(255))")
         self.db.execute("INSERT INTO bar VALUES (:baz)", baz="baz")
         self.assertEqual(self.db.execute("SELECT * FROM bar"), [{"firstname": "baz"}])