SF bug #778964: bad seed in python 2.3 random
The default seed is time.time().
Multiplied by 256 before truncating so that fractional seconds are used.
This way, two successive calls to random.seed() are much more likely
to produce different sequences.
diff --git a/Lib/random.py b/Lib/random.py
index 76dc416..7932ac7 100644
--- a/Lib/random.py
+++ b/Lib/random.py
@@ -94,6 +94,9 @@
If a is not None or an int or long, hash(a) is used instead.
"""
+ if a is None:
+ import time
+ a = long(time.time() * 256) # use fractional seconds
super(Random, self).seed(a)
self.gauss_next = None
diff --git a/Lib/test/test_random.py b/Lib/test/test_random.py
index ea2243d..c9103e8 100644
--- a/Lib/test/test_random.py
+++ b/Lib/test/test_random.py
@@ -20,7 +20,7 @@
def test_autoseed(self):
self.gen.seed()
state1 = self.gen.getstate()
- time.sleep(1.1)
+ time.sleep(0.1)
self.gen.seed() # diffent seeds at different times
state2 = self.gen.getstate()
self.assertNotEqual(state1, state2)
diff --git a/Misc/NEWS b/Misc/NEWS
index 1de08e7..93c7fb8 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -25,6 +25,10 @@
Library
-------
+- random.seed() with no arguments or None uses time.time() as a default
+ seed. Modified to match Py2.2 behavior and use fractional seconds so
+ that successive runs are more likely to produce different sequences.
+
- itertools.izip() with no arguments now returns an empty iterator instead
of raising a TypeError exception.