update documents for set()
@@ -1144,11 +1144,11 @@ class StrictRedis(object):
``px`` sets an expire flag on key ``name`` for ``px`` milliseconds.
- ``nx`` if set to True, set the value at key ``name`` to ``value`` if it
- does not already exist.
+ ``nx`` if set to True, set the value at key ``name`` to ``value`` only
+ if it does not exist.
- ``xx`` if set to True, set the value at key ``name`` to ``value`` if it
- already exists.
+ ``xx`` if set to True, set the value at key ``name`` to ``value`` only
+ if it already exists.
"""
pieces = [name, value]
if ex is not None:
