Hoist the float conversion out of the inner loop. (GH-10430)
Currently, the *n* and *total* variables get converted to floats each time they are multiplied by random(). This minor tweak does the conversion just once and gets a small speedup (approx 3%).
diff --git a/Lib/random.py b/Lib/random.py
index b2c0d6f..4b51b66 100644
--- a/Lib/random.py
+++ b/Lib/random.py
@@ -375,6 +375,7 @@
if cum_weights is None:
if weights is None:
_int = int
+ n += 0.0 # convert to float for a small speed improvement
return [population[_int(random() * n)] for i in range(k)]
cum_weights = list(_itertools.accumulate(weights))
elif weights is not None:
@@ -382,7 +383,7 @@
if len(cum_weights) != n:
raise ValueError('The number of weights does not match the population')
bisect = _bisect.bisect
- total = cum_weights[-1]
+ total = cum_weights[-1] + 0.0 # convert to float
hi = n - 1
return [population[bisect(cum_weights, random() * total, 0, hi)]
for i in range(k)]