[Python-Dev] os.urandom API

[Raymond Hettinger]

I would like to change the API for the new os.urandom(n) function to
return a long integer instead of a string.  The former better serves
more use cases and fits better with existing modules.

In favor of a long integer:

1) The call random.seed(os.random(100)) is a likely use case.  If the
intermediate value is a string, then random.seed() will hash it and only
use 32 bits.  If the intermediate value is a long integer, all bits are
used.  In the given example, the latter is clearly what the user expects
(otherwise, they would only request 4 bytes).

2) Another likely use case is accessing all the tools in the random
module with a subclass that overrides random() and getrandbits().  Both
can be done easier and faster if os.random() returns long integers.  If
the starting point is a string, the code gets ugly and slow.

3) Most use cases for random values involve numeric manipulation.
Simple tasks like finding a random integer in the range [0,100000)
become unnecessarily more complicated when starting from a string.

4) The decimal module supports instantiation directly from long integers
but not from binary strings.


In favor of a string of bytes:

1) This form is handy for cyptoweenies to xor with other byte strings
(perhaps for a one-time pad).



Raymond