Issue #14824: Update Repr.repr_TYPE documentation to use correct name mangling implementation.

Patch by Chris Rebert.

Doc/library/reprlib.rst

@@ -129,9 +129,9 @@ which format specific object types.
 
    Formatting methods for specific types are implemented as methods with a name
    based on the type name.  In the method name, **TYPE** is replaced by
-   ``string.join(string.split(type(obj).__name__, '_'))``. Dispatch to these
-   methods is handled by :meth:`repr1`. Type-specific methods which need to
-   recursively format a value should call ``self.repr1(subobj, level - 1)``.
+   ``'_'.join(type(obj).__name__.split())``. Dispatch to these methods is
+   handled by :meth:`repr1`. Type-specific methods which need to recursively
+   format a value should call ``self.repr1(subobj, level - 1)``.
 
 
 .. _subclassing-reprs: