diff options
Diffstat (limited to 'Lib/random.py')
| -rw-r--r-- | Lib/random.py | 19 |
1 files changed, 14 insertions, 5 deletions
diff --git a/Lib/random.py b/Lib/random.py index 4642928..4efbb0a 100644 --- a/Lib/random.py +++ b/Lib/random.py @@ -96,11 +96,13 @@ class Random(_random.Random): None or no argument seeds from current time or from an operating system specific randomness source if available. - For version 2 (the default), all of the bits are used if *a* is a str, - bytes, or bytearray. For version 1, the hash() of *a* is used instead. - If *a* is an int, all bits are used. + For version 2 (the default), all of the bits are used if *a* is a str, + bytes, or bytearray. For version 1 (provided for reproducing random + sequences from older versions of Python), the algorithm for str and + bytes generates a narrower range of seeds. + """ if a is None: @@ -112,6 +114,13 @@ class Random(_random.Random): import time a = int(time.time() * 256) # use fractional seconds + if version == 1 and isinstance(a, (str, bytes)): + x = ord(a[0]) << 7 if a else 0 + for c in a: + x = ((1000003 * x) ^ ord(c)) & 0xFFFFFFFFFFFFFFFF + x ^= len(a) + a = -2 if x == -1 else x + if version == 2: if isinstance(a, (str, bytes, bytearray)): if isinstance(a, str): @@ -231,7 +240,7 @@ class Random(_random.Random): while r >= n: r = getrandbits(k) return r - # There's an overriden random() method but no new getrandbits() method, + # There's an overridden random() method but no new getrandbits() method, # so we can only use random() from here. if n >= maxsize: _warn("Underlying random() generator does not supply \n" @@ -687,7 +696,7 @@ def _test_generator(n, func, args): 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' % \ + print('avg %g, stddev %g, min %g, max %g\n' % \ (avg, stddev, smallest, largest)) |