sympy: what's wrong with this picture?

[Mensanator]

Notice anything funny about the "random" choices?

import sympy
import time
import random

f = [i for i in sympy.primerange(1000,10000)]

for i in xrange(10):
  f1 = random.choice(f)
  print f1,
  f2 = random.choice(f)
  print f2,
  C = f1*f2
  ff = None
  ff = sympy.factorint(C)
  print ff

##  7307 7243 [(7243, 1), (7307, 1)]
##  4091 6829 [(4091, 1), (6829, 1)]
##  8563 2677 [(2677, 1), (8563, 1)]
##  4091 6829 [(4091, 1), (6829, 1)]
##  8563 2677 [(2677, 1), (8563, 1)]
##  4091 6829 [(4091, 1), (6829, 1)]
##  8563 2677 [(2677, 1), (8563, 1)]
##  4091 6829 [(4091, 1), (6829, 1)]
##  8563 2677 [(2677, 1), (8563, 1)]
##  4091 6829 [(4091, 1), (6829, 1)]

As in, "they're NOT random".

The random number generator is broken by the sympy.factorint()
function.

Random.choice() works ok if the factorint() function commented out.

##  6089 1811 None
##  6449 1759 None
##  9923 4639 None
##  4013 4889 None
##  4349 2029 None
##  6703 8677 None
##  1879 1867 None
##  5153 5279 None
##  2011 4937 None
##  7253 5507 None

This makes sympy worse than worthless, as it fucks up other modules.