# [IPython-dev] Re: [FWD] An interesting take on the Notebook Problem

Robert Kern rkern at ucsd.edu
Mon Aug 1 08:58:39 EDT 2005

```Hans Meine wrote:
> On Friday 22 July 2005 16:05, Toni Alatalo wrote:
>
>>[...] quick Googling now didn't tell me if the Python
>>random generator is guaranteed to give the same results with the same
>>seed and in what conditions (i know from working on procedural modelling
>>that it at least works on the same computer..), but that can be looked
>>at later.
>
> Confusingly, calling "random.seed(...)" is not enough.  A too quick check once
> gave me the impression that it was (the first call of random.random() indeed
> returned the same value), but in order to store/restore the complete state
> you need to use the provided functions random.getstate() and
> random.setstate() which return the state as a a 3-tuple of an int, a tuple
> containing 625 ints and a None here.

random.seed() deterministically sets the whole state from an
integer/long. Calling random.seed() should be enough.

In [1]: import random

In [2]: random.seed(123456789)

In [3]: [random.random() for i in range(20)]
Out[3]:
[0.64140061618587263,
0.54218926809694945,
0.99317506628327212,
0.84325213668691656,
0.81173392833794056,
0.3971737100780004,
0.93709510791204254,
0.6891026531658162,
0.39711048852598374,
0.35102519242304475,
0.399603131718545,
0.54558174824433847,
0.207714227402927,
0.6001575513874905,
0.023680264289157371,
0.61140144008940833,
0.026211036291071466,
0.62015590923237174,
0.73967307701763618,
0.31412119286874374]

In [4]: random.seed(123456789)

In [5]: [random.random() for i in range(20)]
Out[5]:
[0.64140061618587263,
0.54218926809694945,
0.99317506628327212,
0.84325213668691656,
0.81173392833794056,
0.3971737100780004,
0.93709510791204254,
0.6891026531658162,
0.39711048852598374,
0.35102519242304475,
0.399603131718545,
0.54558174824433847,
0.207714227402927,
0.6001575513874905,
0.023680264289157371,
0.61140144008940833,
0.026211036291071466,
0.62015590923237174,
0.73967307701763618,
0.31412119286874374]

--
Robert Kern
rkern at ucsd.edu

"In the fields of hell where the grass grows high
Are the graves of dreams allowed to die."
-- Richard Harter

```