diff options
author | Raymond Hettinger <rhettinger@users.noreply.github.com> | 2020-06-23 02:38:59 (GMT) |
---|---|---|
committer | GitHub <noreply@github.com> | 2020-06-23 02:38:59 (GMT) |
commit | 26a1ad1c24717990265b71ed093d691500d6301c (patch) | |
tree | 282b52f60b274a01d3339108853ea572661bb12f /Lib/random.py | |
parent | a16d6970496cae5ecab5aaea2b416a4b77527cc2 (diff) | |
download | cpython-26a1ad1c24717990265b71ed093d691500d6301c.zip cpython-26a1ad1c24717990265b71ed093d691500d6301c.tar.gz cpython-26a1ad1c24717990265b71ed093d691500d6301c.tar.bz2 |
Small clean-ups for the random module (GH-21038)
Diffstat (limited to 'Lib/random.py')
-rw-r--r-- | Lib/random.py | 57 |
1 files changed, 27 insertions, 30 deletions
diff --git a/Lib/random.py b/Lib/random.py index 02a56c6..ae7b5cf 100644 --- a/Lib/random.py +++ b/Lib/random.py @@ -39,7 +39,8 @@ General notes on the underlying Mersenne Twister core generator: from warnings import warn as _warn from math import log as _log, exp as _exp, pi as _pi, e as _e, ceil as _ceil -from math import sqrt as _sqrt, acos as _acos, cos as _cos, sin as _sin, tau as TWOPI +from math import sqrt as _sqrt, acos as _acos, cos as _cos, sin as _sin +from math import tau as TWOPI, floor as _floor from os import urandom as _urandom from _collections_abc import Set as _Set, Sequence as _Sequence from itertools import accumulate as _accumulate, repeat as _repeat @@ -234,7 +235,7 @@ class Random(_random.Random): ## -------------------- integer methods ------------------- - def randrange(self, start, stop=None, step=1, _int=int): + def randrange(self, start, stop=None, step=1): """Choose a random item from range(start, stop[, step]). This fixes the problem with randint() which includes the @@ -244,7 +245,7 @@ class Random(_random.Random): # This code is a bit messy to make it fast for the # common case while still doing adequate error checking. - istart = _int(start) + istart = int(start) if istart != start: raise ValueError("non-integer arg 1 for randrange()") if stop is None: @@ -253,7 +254,7 @@ class Random(_random.Random): raise ValueError("empty range for randrange()") # stop argument supplied. - istop = _int(stop) + istop = int(stop) if istop != stop: raise ValueError("non-integer stop for randrange()") width = istop - istart @@ -263,7 +264,7 @@ class Random(_random.Random): raise ValueError("empty range for randrange() (%d, %d, %d)" % (istart, istop, width)) # Non-unit step argument supplied. - istep = _int(step) + istep = int(step) if istep != step: raise ValueError("non-integer step for randrange()") if istep > 0: @@ -296,7 +297,7 @@ class Random(_random.Random): r = getrandbits(k) return r - def _randbelow_without_getrandbits(self, n, int=int, maxsize=1<<BPF): + def _randbelow_without_getrandbits(self, n, maxsize=1<<BPF): """Return a random int in the range [0,n). Returns 0 if n==0. The implementation does not use getrandbits, but only random. @@ -307,7 +308,7 @@ class Random(_random.Random): _warn("Underlying random() generator does not supply \n" "enough bits to choose from a population range this large.\n" "To remove the range limitation, add a getrandbits() method.") - return int(random() * n) + return _floor(random() * n) if n == 0: return 0 rem = maxsize % n @@ -315,7 +316,7 @@ class Random(_random.Random): r = random() while r >= limit: r = random() - return int(r * maxsize) % n + return _floor(r * maxsize) % n _randbelow = _randbelow_with_getrandbits @@ -346,10 +347,10 @@ class Random(_random.Random): 'since Python 3.9 and will be removed in a subsequent ' 'version.', DeprecationWarning, 2) - _int = int + floor = _floor for i in reversed(range(1, len(x))): # pick an element in x[:i+1] with which to exchange x[i] - j = _int(random() * (i + 1)) + j = floor(random() * (i + 1)) x[i], x[j] = x[j], x[i] def sample(self, population, k, *, counts=None): @@ -462,9 +463,9 @@ class Random(_random.Random): n = len(population) if cum_weights is None: if weights is None: - _int = int + floor = _floor n += 0.0 # convert to float for a small speed improvement - return [population[_int(random() * n)] for i in _repeat(None, k)] + return [population[floor(random() * n)] for i in _repeat(None, k)] cum_weights = list(_accumulate(weights)) elif weights is not None: raise TypeError('Cannot specify both weights and cumulative weights') @@ -814,24 +815,20 @@ class SystemRandom(Random): ## -------------------- test program -------------------- def _test_generator(n, func, args): - import time - print(n, 'times', func.__name__) - total = 0.0 - sqsum = 0.0 - smallest = 1e10 - largest = -1e10 - t0 = time.perf_counter() - for i in range(n): - x = func(*args) - total += x - sqsum = sqsum + x*x - smallest = min(x, smallest) - largest = max(x, largest) - t1 = time.perf_counter() - print(round(t1 - t0, 3), 'sec,', end=' ') - avg = total / n - stddev = _sqrt(sqsum / n - avg * avg) - print('avg %g, stddev %g, min %g, max %g\n' % (avg, stddev, smallest, largest)) + from statistics import stdev, fmean as mean + from time import perf_counter + + t0 = perf_counter() + data = [func(*args) for i in range(n)] + t1 = perf_counter() + + xbar = mean(data) + sigma = stdev(data, xbar) + low = min(data) + high = max(data) + + print(f'{t1 - t0:.3f} sec, {n} times {func.__name__}') + print('avg %g, stddev %g, min %g, max %g\n' % (xbar, sigma, low, high)) def _test(N=2000): |