Fix typo

Author: hansthen

Doc/library/argparse.rst

@@ -1162,7 +1162,8 @@ Note that, by default, inclusion in the *choices* sequence is checked after
 any type_ conversions have been performed, so the type of the objects in the
 *choices* sequence should match the type_ specified. This can lead to
 confusing ``usage`` messages. If you want to convert *choices* using type_
-before checking, set the ``convert_choices`` flag on :class:'`ArgumentParser`.
+before checking, set the ``convert_choices`` flag on :class:`~ArgumentParser`.
+
 
 Any sequence can be passed as the *choices* value, so :class:`list` objects,
 :class:`tuple` objects, and custom sequences are all supported.