Issue #16641: Fix default values of sched.scheduler.enter arguments were modifiable.
diff --git a/Lib/sched.py b/Lib/sched.py
index e523bc1..4b1f7ac 100644
--- a/Lib/sched.py
+++ b/Lib/sched.py
@@ -50,6 +50,8 @@
def __gt__(s, o): return (s.time, s.priority) > (o.time, o.priority)
def __ge__(s, o): return (s.time, s.priority) >= (o.time, o.priority)
+_sentinel = object()
+
class scheduler:
def __init__(self, timefunc=_time, delayfunc=time.sleep):
@@ -60,19 +62,21 @@
self.timefunc = timefunc
self.delayfunc = delayfunc
- def enterabs(self, time, priority, action, argument=[], kwargs={}):
+ def enterabs(self, time, priority, action, argument=(), kwargs=_sentinel):
"""Enter a new event in the queue at an absolute time.
Returns an ID for the event which can be used to remove it,
if necessary.
"""
+ if kwargs is _sentinel:
+ kwargs = {}
with self._lock:
event = Event(time, priority, action, argument, kwargs)
heapq.heappush(self._queue, event)
return event # The ID
- def enter(self, delay, priority, action, argument=[], kwargs={}):
+ def enter(self, delay, priority, action, argument=(), kwargs=_sentinel):
"""A variant that specifies the time as a relative time.
This is actually the more commonly used interface.