Improved docstrings for str and unicode methods format and __format__.
diff --git a/Objects/stringobject.c b/Objects/stringobject.c
index 347f318..6d3ca8e 100644
--- a/Objects/stringobject.c
+++ b/Objects/stringobject.c
@@ -3582,7 +3582,8 @@
PyDoc_STRVAR(format__doc__,
"S.format(*args, **kwargs) -> string\n\
\n\
-");
+Return a formatted version of S, using substitutions from args and kwargs.\n\
+The substitutions are identified by braces ('{' and '}').");
static PyObject *
string__format__(PyObject* self, PyObject* args)
@@ -3616,7 +3617,7 @@
PyDoc_STRVAR(p_format__doc__,
"S.__format__(format_spec) -> string\n\
\n\
-");
+Return a formatted version of S as described by format_spec.");
static PyMethodDef