diff options
Diffstat (limited to 'Lib/random.py')
| -rw-r--r-- | Lib/random.py | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/Lib/random.py b/Lib/random.py index 3c05086..defddbe 100644 --- a/Lib/random.py +++ b/Lib/random.py @@ -207,7 +207,7 @@ class Random(_random.Random): j = int(random() * (i+1)) x[i], x[j] = x[j], x[i] - def sample(self, population, k, int=int): + def sample(self, population, k): """Chooses k unique random elements from a population sequence. Returns a new list containing elements from the population while @@ -240,19 +240,20 @@ class Random(_random.Random): if not 0 <= k <= n: raise ValueError, "sample larger than population" random = self.random + _int = int result = [None] * k if n < 6 * k: # if n len list takes less space than a k len dict pool = list(population) for i in xrange(k): # invariant: non-selected at [0,n-i) - j = int(random() * (n-i)) + j = _int(random() * (n-i)) result[i] = pool[j] pool[j] = pool[n-i-1] # move non-selected item into vacancy else: selected = {} for i in xrange(k): - j = int(random() * n) + j = _int(random() * n) while j in selected: - j = int(random() * n) + j = _int(random() * n) result[i] = selected[j] = population[j] return result |