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Code Issues Releases Wiki Activity

More exhaustive combinatoric checks.

This commit is contained in:
Raymond Hettinger 2009-01-27 10:36:14 +00:00
parent ecf252abac
commit 2f6c2e03a8
1 changed files with 27 additions and 15 deletions
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18
Lib/test/test_itertools.py
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@ -274,15 +274,27 @@ class TestBasicOps(unittest.TestCase):
# Test relationships between product(), permutations(),
# combinations() and combinations_with_replacement().
s = 'ABCDE'
for n in range(6):
s = 'ABCDEFG'[:n]
for r in range(8):
prod = list(product(s, repeat=r))
cwr = list(combinations_with_replacement(s, r))
perm = list(permutations(s, r))
comb = list(combinations(s, r))
self.assertEquals(len(prod), len(s)**r)
self.assertEquals(prod, sorted(set(prod))) # prod in lexicographic order without repeats
# Check size
self.assertEquals(len(prod), n**r)
self.assertEquals(len(cwr), (fact(n+r-1) / fact(r)/ fact(n-1)) if n else (not r))
self.assertEquals(len(perm), 0 if r>n else fact(n) / fact(n-r))
self.assertEquals(len(comb), 0 if r>n else fact(n) / fact(r) / fact(n-r))
# Check lexicographic order without repeated tuples
self.assertEquals(prod, sorted(set(prod)))
self.assertEquals(cwr, sorted(set(cwr)))
self.assertEquals(perm, sorted(set(perm)))
self.assertEquals(comb, sorted(set(comb)))
# Check interrelationships
self.assertEquals(cwr, [t for t in prod if sorted(t)==list(t)]) # cwr: prods which are sorted
self.assertEquals(perm, [t for t in prod if len(set(t))==r]) # perm: prods with no dups
self.assertEqual(comb, [t for t in perm if sorted(t)==list(t)]) # comb: perms that are sorted