Last round of adapting style of documenting argument default values.
diff --git a/Doc/library/string.rst b/Doc/library/string.rst
index 8098651..3466af6 100644
--- a/Doc/library/string.rst
+++ b/Doc/library/string.rst
@@ -479,19 +479,19 @@
The constructor takes a single argument which is the template string.
- .. method:: substitute(mapping[, **kws])
+ .. method:: substitute(mapping, **kwds)
Performs the template substitution, returning a new string. *mapping* is
any dictionary-like object with keys that match the placeholders in the
template. Alternatively, you can provide keyword arguments, where the
- keywords are the placeholders. When both *mapping* and *kws* are given
- and there are duplicates, the placeholders from *kws* take precedence.
+ keywords are the placeholders. When both *mapping* and *kwds* are given
+ and there are duplicates, the placeholders from *kwds* take precedence.
- .. method:: safe_substitute(mapping[, **kws])
+ .. method:: safe_substitute(mapping, **kwds)
Like :meth:`substitute`, except that if placeholders are missing from
- *mapping* and *kws*, instead of raising a :exc:`KeyError` exception, the
+ *mapping* and *kwds*, instead of raising a :exc:`KeyError` exception, the
original placeholder will appear in the resulting string intact. Also,
unlike with :meth:`substitute`, any other appearances of the ``$`` will
simply return ``$`` instead of raising :exc:`ValueError`.