import unittest from test import test_support from itertools import * from weakref import proxy from decimal import Decimal from fractions import Fraction import sys import operator import random maxsize = test_support.MAX_Py_ssize_t minsize = -maxsize-1 def onearg(x): 'Test function of one argument' return 2*x def errfunc(*args): 'Test function that raises an error' raise ValueError def gen3(): 'Non-restartable source sequence' for i in (0, 1, 2): yield i def isEven(x): 'Test predicate' return x%2==0 def isOdd(x): 'Test predicate' return x%2==1 class StopNow: 'Class emulating an empty iterable.' def __iter__(self): return self def next(self): raise StopIteration def take(n, seq): 'Convenience function for partially consuming a long of infinite iterable' return list(islice(seq, n)) def prod(iterable): return reduce(operator.mul, iterable, 1) def fact(n): 'Factorial' return prod(range(1, n+1)) class TestBasicOps(unittest.TestCase): def test_chain(self): def chain2(*iterables): 'Pure python version in the docs' for it in iterables: for element in it: yield element for c in (chain, chain2): self.assertEqual(list(c('abc', 'def')), list('abcdef')) self.assertEqual(list(c('abc')), list('abc')) self.assertEqual(list(c('')), []) self.assertEqual(take(4, c('abc', 'def')), list('abcd')) self.assertRaises(TypeError, list,c(2, 3)) def test_chain_from_iterable(self): self.assertEqual(list(chain.from_iterable(['abc', 'def'])), list('abcdef')) self.assertEqual(list(chain.from_iterable(['abc'])), list('abc')) self.assertEqual(list(chain.from_iterable([''])), []) self.assertEqual(take(4, chain.from_iterable(['abc', 'def'])), list('abcd')) self.assertRaises(TypeError, list, chain.from_iterable([2, 3])) def test_combinations(self): self.assertRaises(TypeError, combinations, 'abc') # missing r argument self.assertRaises(TypeError, combinations, 'abc', 2, 1) # too many arguments self.assertRaises(TypeError, combinations, None) # pool is not iterable self.assertRaises(ValueError, combinations, 'abc', -2) # r is negative self.assertEqual(list(combinations('abc', 32)), []) # r > n self.assertEqual(list(combinations(range(4), 3)), [(0,1,2), (0,1,3), (0,2,3), (1,2,3)]) def combinations1(iterable, r): 'Pure python version shown in the docs' pool = tuple(iterable) n = len(pool) if r > n: return indices = range(r) yield tuple(pool[i] for i in indices) while 1: for i in reversed(range(r)): if indices[i] != i + n - r: break else: return indices[i] += 1 for j in range(i+1, r): indices[j] = indices[j-1] + 1 yield tuple(pool[i] for i in indices) def combinations2(iterable, r): 'Pure python version shown in the docs' pool = tuple(iterable) n = len(pool) for indices in permutations(range(n), r): if sorted(indices) == list(indices): yield tuple(pool[i] for i in indices) def combinations3(iterable, r): 'Pure python version from cwr()' pool = tuple(iterable) n = len(pool) for indices in combinations_with_replacement(range(n), r): if len(set(indices)) == r: yield tuple(pool[i] for i in indices) for n in range(7): values = [5*x-12 for x in range(n)] for r in range(n+2): result = list(combinations(values, r)) self.assertEqual(len(result), 0 if r>n else fact(n) / fact(r) / fact(n-r)) # right number of combs self.assertEqual(len(result), len(set(result))) # no repeats self.assertEqual(result, sorted(result)) # lexicographic order for c in result: self.assertEqual(len(c), r) # r-length combinations self.assertEqual(len(set(c)), r) # no duplicate elements self.assertEqual(list(c), sorted(c)) # keep original ordering self.assertTrue(all(e in values for e in c)) # elements taken from input iterable self.assertEqual(list(c), [e for e in values if e in c]) # comb is a subsequence of the input iterable self.assertEqual(result, list(combinations1(values, r))) # matches first pure python version self.assertEqual(result, list(combinations2(values, r))) # matches second pure python version self.assertEqual(result, list(combinations3(values, r))) # matches second pure python version # Test implementation detail: tuple re-use self.assertEqual(len(set(map(id, combinations('abcde', 3)))), 1) self.assertNotEqual(len(set(map(id, list(combinations('abcde', 3))))), 1) def test_combinations_with_replacement(self): cwr = combinations_with_replacement self.assertRaises(TypeError, cwr, 'abc') # missing r argument self.assertRaises(TypeError, cwr, 'abc', 2, 1) # too many arguments self.assertRaises(TypeError, cwr, None) # pool is not iterable self.assertRaises(ValueError, cwr, 'abc', -2) # r is negative self.assertEqual(list(cwr('ABC', 2)), [('A','A'), ('A','B'), ('A','C'), ('B','B'), ('B','C'), ('C','C')]) def cwr1(iterable, r): 'Pure python version shown in the docs' # number items returned: (n+r-1)! / r! / (n-1)! when n>0 pool = tuple(iterable) n = len(pool) if not n and r: return indices = [0] * r yield tuple(pool[i] for i in indices) while 1: for i in reversed(range(r)): if indices[i] != n - 1: break else: return indices[i:] = [indices[i] + 1] * (r - i) yield tuple(pool[i] for i in indices) def cwr2(iterable, r): 'Pure python version shown in the docs' pool = tuple(iterable) n = len(pool) for indices in product(range(n), repeat=r): if sorted(indices) == list(indices): yield tuple(pool[i] for i in indices) def numcombs(n, r): if not n: return 0 if r else 1 return fact(n+r-1) / fact(r)/ fact(n-1) for n in range(7): values = [5*x-12 for x in range(n)] for r in range(n+2): result = list(cwr(values, r)) self.assertEqual(len(result), numcombs(n, r)) # right number of combs self.assertEqual(len(result), len(set(result))) # no repeats self.assertEqual(result, sorted(result)) # lexicographic order regular_combs = list(combinations(values, r)) # compare to combs without replacement if n == 0 or r <= 1: self.assertEquals(result, regular_combs) # cases that should be identical else: self.assertTrue(set(result) >= set(regular_combs)) # rest should be supersets of regular combs for c in result: self.assertEqual(len(c), r) # r-length combinations noruns = [k for k,v in groupby(c)] # combo without consecutive repeats self.assertEqual(len(noruns), len(set(noruns))) # no repeats other than consecutive self.assertEqual(list(c), sorted(c)) # keep original ordering self.assertTrue(all(e in values for e in c)) # elements taken from input iterable self.assertEqual(noruns, [e for e in values if e in c]) # comb is a subsequence of the input iterable self.assertEqual(result, list(cwr1(values, r))) # matches first pure python version self.assertEqual(result, list(cwr2(values, r))) # matches second pure python version # Test implementation detail: tuple re-use self.assertEqual(len(set(map(id, cwr('abcde', 3)))), 1) self.assertNotEqual(len(set(map(id, list(cwr('abcde', 3))))), 1) def test_permutations(self): self.assertRaises(TypeError, permutations) # too few arguments self.assertRaises(TypeError, permutations, 'abc', 2, 1) # too many arguments self.assertRaises(TypeError, permutations, None) # pool is not iterable self.assertRaises(ValueError, permutations, 'abc', -2) # r is negative self.assertEqual(list(permutations('abc', 32)), []) # r > n self.assertRaises(TypeError, permutations, 'abc', 's') # r is not an int or None self.assertEqual(list(permutations(range(3), 2)), [(0,1), (0,2), (1,0), (1,2), (2,0), (2,1)]) def permutations1(iterable, r=None): 'Pure python version shown in the docs' pool = tuple(iterable) n = len(pool) r = n if r is None else r if r > n: return indices = range(n) cycles = range(n, n-r, -1) yield tuple(pool[i] for i in indices[:r]) while n: for i in reversed(range(r)): cycles[i] -= 1 if cycles[i] == 0: indices[i:] = indices[i+1:] + indices[i:i+1] cycles[i] = n - i else: j = cycles[i] indices[i], indices[-j] = indices[-j], indices[i] yield tuple(pool[i] for i in indices[:r]) break else: return def permutations2(iterable, r=None): 'Pure python version shown in the docs' pool = tuple(iterable) n = len(pool) r = n if r is None else r for indices in product(range(n), repeat=r): if len(set(indices)) == r: yield tuple(pool[i] for i in indices) for n in range(7): values = [5*x-12 for x in range(n)] for r in range(n+2): result = list(permutations(values, r)) self.assertEqual(len(result), 0 if r>n else fact(n) / fact(n-r)) # right number of perms self.assertEqual(len(result), len(set(result))) # no repeats self.assertEqual(result, sorted(result)) # lexicographic order for p in result: self.assertEqual(len(p), r) # r-length permutations self.assertEqual(len(set(p)), r) # no duplicate elements self.assertTrue(all(e in values for e in p)) # elements taken from input iterable self.assertEqual(result, list(permutations1(values, r))) # matches first pure python version self.assertEqual(result, list(permutations2(values, r))) # matches second pure python version if r == n: self.assertEqual(result, list(permutations(values, None))) # test r as None self.assertEqual(result, list(permutations(values))) # test default r # Test implementation detail: tuple re-use self.assertEqual(len(set(map(id, permutations('abcde', 3)))), 1) self.assertNotEqual(len(set(map(id, list(permutations('abcde', 3))))), 1) def test_combinatorics(self): # Test relationships between product(), permutations(), # combinations() and combinations_with_replacement(). 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)) # 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 self.assertEqual(comb, [t for t in cwr if len(set(t))==r]) # comb: cwrs without dups self.assertEqual(comb, filter(set(cwr).__contains__, perm)) # comb: perm that is a cwr self.assertEqual(comb, filter(set(perm).__contains__, cwr)) # comb: cwr that is a perm self.assertEqual(comb, sorted(set(cwr) & set(perm))) # comb: both a cwr and a perm def test_compress(self): self.assertEqual(list(compress(data='ABCDEF', selectors=[1,0,1,0,1,1])), list('ACEF')) self.assertEqual(list(compress('ABCDEF', [1,0,1,0,1,1])), list('ACEF')) self.assertEqual(list(compress('ABCDEF', [0,0,0,0,0,0])), list('')) self.assertEqual(list(compress('ABCDEF', [1,1,1,1,1,1])), list('ABCDEF')) self.assertEqual(list(compress('ABCDEF', [1,0,1])), list('AC')) self.assertEqual(list(compress('ABC', [0,1,1,1,1,1])), list('BC')) n = 10000 data = chain.from_iterable(repeat(range(6), n)) selectors = chain.from_iterable(repeat((0, 1))) self.assertEqual(list(compress(data, selectors)), [1,3,5] * n) self.assertRaises(TypeError, compress, None, range(6)) # 1st arg not iterable self.assertRaises(TypeError, compress, range(6), None) # 2nd arg not iterable self.assertRaises(TypeError, compress, range(6)) # too few args self.assertRaises(TypeError, compress, range(6), None) # too many args def test_count(self): self.assertEqual(zip('abc',count()), [('a', 0), ('b', 1), ('c', 2)]) self.assertEqual(zip('abc',count(3)), [('a', 3), ('b', 4), ('c', 5)]) self.assertEqual(take(2, zip('abc',count(3))), [('a', 3), ('b', 4)]) self.assertEqual(take(2, zip('abc',count(-1))), [('a', -1), ('b', 0)]) self.assertEqual(take(2, zip('abc',count(-3))), [('a', -3), ('b', -2)]) self.assertRaises(TypeError, count, 2, 3, 4) self.assertRaises(TypeError, count, 'a') self.assertEqual(list(islice(count(maxsize-5), 10)), range(maxsize-5, maxsize+5)) self.assertEqual(list(islice(count(-maxsize-5), 10)), range(-maxsize-5, -maxsize+5)) c = count(3) self.assertEqual(repr(c), 'count(3)') c.next() self.assertEqual(repr(c), 'count(4)') c = count(-9) self.assertEqual(repr(c), 'count(-9)') c.next() self.assertEqual(repr(count(10.25)), 'count(10.25)') self.assertEqual(c.next(), -8) for i in (-sys.maxint-5, -sys.maxint+5 ,-10, -1, 0, 10, sys.maxint-5, sys.maxint+5): # Test repr (ignoring the L in longs) r1 = repr(count(i)).replace('L', '') r2 = 'count(%r)'.__mod__(i).replace('L', '') self.assertEqual(r1, r2) def test_count_with_stride(self): self.assertEqual(zip('abc',count(2,3)), [('a', 2), ('b', 5), ('c', 8)]) self.assertEqual(zip('abc',count(start=2,step=3)), [('a', 2), ('b', 5), ('c', 8)]) self.assertEqual(zip('abc',count(step=-1)), [('a', 0), ('b', -1), ('c', -2)]) self.assertEqual(zip('abc',count(2,0)), [('a', 2), ('b', 2), ('c', 2)]) self.assertEqual(zip('abc',count(2,1)), [('a', 2), ('b', 3), ('c', 4)]) self.assertEqual(take(20, count(maxsize-15, 3)), take(20, range(maxsize-15, maxsize+100, 3))) self.assertEqual(take(20, count(-maxsize-15, 3)), take(20, range(-maxsize-15,-maxsize+100, 3))) self.assertEqual(take(3, count(2, 3.25-4j)), [2, 5.25-4j, 8.5-8j]) self.assertEqual(take(3, count(Decimal('1.1'), Decimal('.1'))), [Decimal('1.1'), Decimal('1.2'), Decimal('1.3')]) self.assertEqual(take(3, count(Fraction(2,3), Fraction(1,7))), [Fraction(2,3), Fraction(17,21), Fraction(20,21)]) self.assertEqual(repr(take(3, count(10, 2.5))), repr([10, 12.5, 15.0])) c = count(3, 5) self.assertEqual(repr(c), 'count(3, 5)') c.next() self.assertEqual(repr(c), 'count(8, 5)') c = count(-9, 0) self.assertEqual(repr(c), 'count(-9, 0)') c.next() self.assertEqual(repr(c), 'count(-9, 0)') c = count(-9, -3) self.assertEqual(repr(c), 'count(-9, -3)') c.next() self.assertEqual(repr(c), 'count(-12, -3)') self.assertEqual(repr(c), 'count(-12, -3)') self.assertEqual(repr(count(10.5, 1.25)), 'count(10.5, 1.25)') self.assertEqual(repr(count(10.5, 1)), 'count(10.5)') # suppress step=1 when it's an int self.assertEqual(repr(count(10.5, 1.00)), 'count(10.5, 1.0)') # do show float values lilke 1.0 for i in (-sys.maxint-5, -sys.maxint+5 ,-10, -1, 0, 10, sys.maxint-5, sys.maxint+5): for j in (-sys.maxint-5, -sys.maxint+5 ,-10, -1, 0, 1, 10, sys.maxint-5, sys.maxint+5): # Test repr (ignoring the L in longs) r1 = repr(count(i, j)).replace('L', '') if j == 1: r2 = ('count(%r)' % i).replace('L', '') else: r2 = ('count(%r, %r)' % (i, j)).replace('L', '') self.assertEqual(r1, r2) def test_cycle(self): self.assertEqual(take(10, cycle('abc')), list('abcabcabca')) self.assertEqual(list(cycle('')), []) self.assertRaises(TypeError, cycle) self.assertRaises(TypeError, cycle, 5) self.assertEqual(list(islice(cycle(gen3()),10)), [0,1,2,0,1,2,0,1,2,0]) def test_groupby(self): # Check whether it accepts arguments correctly self.assertEqual([], list(groupby([]))) self.assertEqual([], list(groupby([], key=id))) self.assertRaises(TypeError, list, groupby('abc', [])) self.assertRaises(TypeError, groupby, None) self.assertRaises(TypeError, groupby, 'abc', lambda x:x, 10) # Check normal input s = [(0, 10, 20), (0, 11,21), (0,12,21), (1,13,21), (1,14,22), (2,15,22), (3,16,23), (3,17,23)] dup = [] for k, g in groupby(s, lambda r:r[0]): for elem in g: self.assertEqual(k, elem[0]) dup.append(elem) self.assertEqual(s, dup) # Check nested case dup = [] for k, g in groupby(s, lambda r:r[0]): for ik, ig in groupby(g, lambda r:r[2]): for elem in ig: self.assertEqual(k, elem[0]) self.assertEqual(ik, elem[2]) dup.append(elem) self.assertEqual(s, dup) # Check case where inner iterator is not used keys = [k for k, g in groupby(s, lambda r:r[0])] expectedkeys = set([r[0] for r in s]) self.assertEqual(set(keys), expectedkeys) self.assertEqual(len(keys), len(expectedkeys)) # Exercise pipes and filters style s = 'abracadabra' # sort s | uniq r = [k for k, g in groupby(sorted(s))] self.assertEqual(r, ['a', 'b', 'c', 'd', 'r']) # sort s | uniq -d r = [k for k, g in groupby(sorted(s)) if list(islice(g,1,2))] self.assertEqual(r, ['a', 'b', 'r']) # sort s | uniq -c r = [(len(list(g)), k) for k, g in groupby(sorted(s))] self.assertEqual(r, [(5, 'a'), (2, 'b'), (1, 'c'), (1, 'd'), (2, 'r')]) # sort s | uniq -c | sort -rn | head -3 r = sorted([(len(list(g)) , k) for k, g in groupby(sorted(s))], reverse=True)[:3] self.assertEqual(r, [(5, 'a'), (2, 'r'), (2, 'b')]) # iter.next failure class ExpectedError(Exception): pass def delayed_raise(n=0): for i in range(n): yield 'yo' raise ExpectedError def gulp(iterable, keyp=None, func=list): return [func(g) for k, g in groupby(iterable, keyp)] # iter.next failure on outer object self.assertRaises(ExpectedError, gulp, delayed_raise(0)) # iter.next failure on inner object self.assertRaises(ExpectedError, gulp, delayed_raise(1)) # __cmp__ failure class DummyCmp: def __cmp__(self, dst): raise ExpectedError s = [DummyCmp(), DummyCmp(), None] # __cmp__ failure on outer object self.assertRaises(ExpectedError, gulp, s, func=id) # __cmp__ failure on inner object self.assertRaises(ExpectedError, gulp, s) # keyfunc failure def keyfunc(obj): if keyfunc.skip > 0: keyfunc.skip -= 1 return obj else: raise ExpectedError # keyfunc failure on outer object keyfunc.skip = 0 self.assertRaises(ExpectedError, gulp, [None], keyfunc) keyfunc.skip = 1 self.assertRaises(ExpectedError, gulp, [None, None], keyfunc) def test_ifilter(self): self.assertEqual(list(ifilter(isEven, range(6))), [0,2,4]) self.assertEqual(list(ifilter(None, [0,1,0,2,0])), [1,2]) self.assertEqual(list(ifilter(bool, [0,1,0,2,0])), [1,2]) self.assertEqual(take(4, ifilter(isEven, count())), [0,2,4,6]) self.assertRaises(TypeError, ifilter) self.assertRaises(TypeError, ifilter, lambda x:x) self.assertRaises(TypeError, ifilter, lambda x:x, range(6), 7) self.assertRaises(TypeError, ifilter, isEven, 3) self.assertRaises(TypeError, ifilter(range(6), range(6)).next) def test_ifilterfalse(self): self.assertEqual(list(ifilterfalse(isEven, range(6))), [1,3,5]) self.assertEqual(list(ifilterfalse(None, [0,1,0,2,0])), [0,0,0]) self.assertEqual(list(ifilterfalse(bool, [0,1,0,2,0])), [0,0,0]) self.assertEqual(take(4, ifilterfalse(isEven, count())), [1,3,5,7]) self.assertRaises(TypeError, ifilterfalse) self.assertRaises(TypeError, ifilterfalse, lambda x:x) self.assertRaises(TypeError, ifilterfalse, lambda x:x, range(6), 7) self.assertRaises(TypeError, ifilterfalse, isEven, 3) self.assertRaises(TypeError, ifilterfalse(range(6), range(6)).next) def test_izip(self): ans = [(x,y) for x, y in izip('abc',count())] self.assertEqual(ans, [('a', 0), ('b', 1), ('c', 2)]) self.assertEqual(list(izip('abc', range(6))), zip('abc', range(6))) self.assertEqual(list(izip('abcdef', range(3))), zip('abcdef', range(3))) self.assertEqual(take(3,izip('abcdef', count())), zip('abcdef', range(3))) self.assertEqual(list(izip('abcdef')), zip('abcdef')) self.assertEqual(list(izip()), zip()) self.assertRaises(TypeError, izip, 3) self.assertRaises(TypeError, izip, range(3), 3) # Check tuple re-use (implementation detail) self.assertEqual([tuple(list(pair)) for pair in izip('abc', 'def')], zip('abc', 'def')) self.assertEqual([pair for pair in izip('abc', 'def')], zip('abc', 'def')) ids = map(id, izip('abc', 'def')) self.assertEqual(min(ids), max(ids)) ids = map(id, list(izip('abc', 'def'))) self.assertEqual(len(dict.fromkeys(ids)), len(ids)) def test_iziplongest(self): for args in [ ['abc', range(6)], [range(6), 'abc'], [range(1000), range(2000,2100), range(3000,3050)], [range(1000), range(0), range(3000,3050), range(1200), range(1500)], [range(1000), range(0), range(3000,3050), range(1200), range(1500), range(0)], ]: target = map(None, *args) self.assertEqual(list(izip_longest(*args)), target) self.assertEqual(list(izip_longest(*args, **{})), target) target = [tuple((e is None and 'X' or e) for e in t) for t in target] # Replace None fills with 'X' self.assertEqual(list(izip_longest(*args, **dict(fillvalue='X'))), target) self.assertEqual(take(3,izip_longest('abcdef', count())), zip('abcdef', range(3))) # take 3 from infinite input self.assertEqual(list(izip_longest()), zip()) self.assertEqual(list(izip_longest([])), zip([])) self.assertEqual(list(izip_longest('abcdef')), zip('abcdef')) self.assertEqual(list(izip_longest('abc', 'defg', **{})), map(None, 'abc', 'defg')) # empty keyword dict self.assertRaises(TypeError, izip_longest, 3) self.assertRaises(TypeError, izip_longest, range(3), 3) for stmt in [ "izip_longest('abc', fv=1)", "izip_longest('abc', fillvalue=1, bogus_keyword=None)", ]: try: eval(stmt, globals(), locals()) except TypeError: pass else: self.fail('Did not raise Type in: ' + stmt) # Check tuple re-use (implementation detail) self.assertEqual([tuple(list(pair)) for pair in izip_longest('abc', 'def')], zip('abc', 'def')) self.assertEqual([pair for pair in izip_longest('abc', 'def')], zip('abc', 'def')) ids = map(id, izip_longest('abc', 'def')) self.assertEqual(min(ids), max(ids)) ids = map(id, list(izip_longest('abc', 'def'))) self.assertEqual(len(dict.fromkeys(ids)), len(ids)) def test_product(self): for args, result in [ ([], [()]), # zero iterables (['ab'], [('a',), ('b',)]), # one iterable ([range(2), range(3)], [(0,0), (0,1), (0,2), (1,0), (1,1), (1,2)]), # two iterables ([range(0), range(2), range(3)], []), # first iterable with zero length ([range(2), range(0), range(3)], []), # middle iterable with zero length ([range(2), range(3), range(0)], []), # last iterable with zero length ]: self.assertEqual(list(product(*args)), result) for r in range(4): self.assertEqual(list(product(*(args*r))), list(product(*args, **dict(repeat=r)))) self.assertEqual(len(list(product(*[range(7)]*6))), 7**6) self.assertRaises(TypeError, product, range(6), None) def product1(*args, **kwds): pools = map(tuple, args) * kwds.get('repeat', 1) n = len(pools) if n == 0: yield () return if any(len(pool) == 0 for pool in pools): return indices = [0] * n yield tuple(pool[i] for pool, i in zip(pools, indices)) while 1: for i in reversed(range(n)): # right to left if indices[i] == len(pools[i]) - 1: continue indices[i] += 1 for j in range(i+1, n): indices[j] = 0 yield tuple(pool[i] for pool, i in zip(pools, indices)) break else: return def product2(*args, **kwds): 'Pure python version used in docs' pools = map(tuple, args) * kwds.get('repeat', 1) result = [[]] for pool in pools: result = [x+[y] for x in result for y in pool] for prod in result: yield tuple(prod) argtypes = ['', 'abc', '', xrange(0), xrange(4), dict(a=1, b=2, c=3), set('abcdefg'), range(11), tuple(range(13))] for i in range(100): args = [random.choice(argtypes) for j in range(random.randrange(5))] expected_len = prod(map(len, args)) self.assertEqual(len(list(product(*args))), expected_len) self.assertEqual(list(product(*args)), list(product1(*args))) self.assertEqual(list(product(*args)), list(product2(*args))) args = map(iter, args) self.assertEqual(len(list(product(*args))), expected_len) # Test implementation detail: tuple re-use self.assertEqual(len(set(map(id, product('abc', 'def')))), 1) self.assertNotEqual(len(set(map(id, list(product('abc', 'def'))))), 1) def test_repeat(self): self.assertEqual(list(repeat(object='a', times=3)), ['a', 'a', 'a']) self.assertEqual(zip(xrange(3),repeat('a')), [(0, 'a'), (1, 'a'), (2, 'a')]) self.assertEqual(list(repeat('a', 3)), ['a', 'a', 'a']) self.assertEqual(take(3, repeat('a')), ['a', 'a', 'a']) self.assertEqual(list(repeat('a', 0)), []) self.assertEqual(list(repeat('a', -3)), []) self.assertRaises(TypeError, repeat) self.assertRaises(TypeError, repeat, None, 3, 4) self.assertRaises(TypeError, repeat, None, 'a') r = repeat(1+0j) self.assertEqual(repr(r), 'repeat((1+0j))') r = repeat(1+0j, 5) self.assertEqual(repr(r), 'repeat((1+0j), 5)') list(r) self.assertEqual(repr(r), 'repeat((1+0j), 0)') def test_imap(self): self.assertEqual(list(imap(operator.pow, range(3), range(1,7))), [0**1, 1**2, 2**3]) self.assertEqual(list(imap(None, 'abc', range(5))), [('a',0),('b',1),('c',2)]) self.assertEqual(list(imap(None, 'abc', count())), [('a',0),('b',1),('c',2)]) self.assertEqual(take(2,imap(None, 'abc', count())), [('a',0),('b',1)]) self.assertEqual(list(imap(operator.pow, [])), []) self.assertRaises(TypeError, imap) self.assertRaises(TypeError, imap, operator.neg) self.assertRaises(TypeError, imap(10, range(5)).next) self.assertRaises(ValueError, imap(errfunc, [4], [5]).next) self.assertRaises(TypeError, imap(onearg, [4], [5]).next) def test_starmap(self): self.assertEqual(list(starmap(operator.pow, zip(range(3), range(1,7)))), [0**1, 1**2, 2**3]) self.assertEqual(take(3, starmap(operator.pow, izip(count(), count(1)))), [0**1, 1**2, 2**3]) self.assertEqual(list(starmap(operator.pow, [])), []) self.assertEqual(list(starmap(operator.pow, [iter([4,5])])), [4**5]) self.assertRaises(TypeError, list, starmap(operator.pow, [None])) self.assertRaises(TypeError, starmap) self.assertRaises(TypeError, starmap, operator.pow, [(4,5)], 'extra') self.assertRaises(TypeError, starmap(10, [(4,5)]).next) self.assertRaises(ValueError, starmap(errfunc, [(4,5)]).next) self.assertRaises(TypeError, starmap(onearg, [(4,5)]).next) def test_islice(self): for args in [ # islice(args) should agree with range(args) (10, 20, 3), (10, 3, 20), (10, 20), (10, 3), (20,) ]: self.assertEqual(list(islice(xrange(100), *args)), range(*args)) for args, tgtargs in [ # Stop when seqn is exhausted ((10, 110, 3), ((10, 100, 3))), ((10, 110), ((10, 100))), ((110,), (100,)) ]: self.assertEqual(list(islice(xrange(100), *args)), range(*tgtargs)) # Test stop=None self.assertEqual(list(islice(xrange(10), None)), range(10)) self.assertEqual(list(islice(xrange(10), None, None)), range(10)) self.assertEqual(list(islice(xrange(10), None, None, None)), range(10)) self.assertEqual(list(islice(xrange(10), 2, None)), range(2, 10)) self.assertEqual(list(islice(xrange(10), 1, None, 2)), range(1, 10, 2)) # Test number of items consumed SF #1171417 it = iter(range(10)) self.assertEqual(list(islice(it, 3)), range(3)) self.assertEqual(list(it), range(3, 10)) # Test invalid arguments self.assertRaises(TypeError, islice, xrange(10)) self.assertRaises(TypeError, islice, xrange(10), 1, 2, 3, 4) self.assertRaises(ValueError, islice, xrange(10), -5, 10, 1) self.assertRaises(ValueError, islice, xrange(10), 1, -5, -1) self.assertRaises(ValueError, islice, xrange(10), 1, 10, -1) self.assertRaises(ValueError, islice, xrange(10), 1, 10, 0) self.assertRaises(ValueError, islice, xrange(10), 'a') self.assertRaises(ValueError, islice, xrange(10), 'a', 1) self.assertRaises(ValueError, islice, xrange(10), 1, 'a') self.assertRaises(ValueError, islice, xrange(10), 'a', 1, 1) self.assertRaises(ValueError, islice, xrange(10), 1, 'a', 1) self.assertEqual(len(list(islice(count(), 1, 10, maxsize))), 1) def test_takewhile(self): data = [1, 3, 5, 20, 2, 4, 6, 8] underten = lambda x: x<10 self.assertEqual(list(takewhile(underten, data)), [1, 3, 5]) self.assertEqual(list(takewhile(underten, [])), []) self.assertRaises(TypeError, takewhile) self.assertRaises(TypeError, takewhile, operator.pow) self.assertRaises(TypeError, takewhile, operator.pow, [(4,5)], 'extra') self.assertRaises(TypeError, takewhile(10, [(4,5)]).next) self.assertRaises(ValueError, takewhile(errfunc, [(4,5)]).next) t = takewhile(bool, [1, 1, 1, 0, 0, 0]) self.assertEqual(list(t), [1, 1, 1]) self.assertRaises(StopIteration, t.next) def test_dropwhile(self): data = [1, 3, 5, 20, 2, 4, 6, 8] underten = lambda x: x<10 self.assertEqual(list(dropwhile(underten, data)), [20, 2, 4, 6, 8]) self.assertEqual(list(dropwhile(underten, [])), []) self.assertRaises(TypeError, dropwhile) self.assertRaises(TypeError, dropwhile, operator.pow) self.assertRaises(TypeError, dropwhile, operator.pow, [(4,5)], 'extra') self.assertRaises(TypeError, dropwhile(10, [(4,5)]).next) self.assertRaises(ValueError, dropwhile(errfunc, [(4,5)]).next) def test_tee(self): n = 200 def irange(n): for i in xrange(n): yield i a, b = tee([]) # test empty iterator self.assertEqual(list(a), []) self.assertEqual(list(b), []) a, b = tee(irange(n)) # test 100% interleaved self.assertEqual(zip(a,b), zip(range(n),range(n))) a, b = tee(irange(n)) # test 0% interleaved self.assertEqual(list(a), range(n)) self.assertEqual(list(b), range(n)) a, b = tee(irange(n)) # test dealloc of leading iterator for i in xrange(100): self.assertEqual(a.next(), i) del a self.assertEqual(list(b), range(n)) a, b = tee(irange(n)) # test dealloc of trailing iterator for i in xrange(100): self.assertEqual(a.next(), i) del b self.assertEqual(list(a), range(100, n)) for j in xrange(5): # test randomly interleaved order = [0]*n + [1]*n random.shuffle(order) lists = ([], []) its = tee(irange(n)) for i in order: value = its[i].next() lists[i].append(value) self.assertEqual(lists[0], range(n)) self.assertEqual(lists[1], range(n)) # test argument format checking self.assertRaises(TypeError, tee) self.assertRaises(TypeError, tee, 3) self.assertRaises(TypeError, tee, [1,2], 'x') self.assertRaises(TypeError, tee, [1,2], 3, 'x') # tee object should be instantiable a, b = tee('abc') c = type(a)('def') self.assertEqual(list(c), list('def')) # test long-lagged and multi-way split a, b, c = tee(xrange(2000), 3) for i in xrange(100): self.assertEqual(a.next(), i) self.assertEqual(list(b), range(2000)) self.assertEqual([c.next(), c.next()], range(2)) self.assertEqual(list(a), range(100,2000)) self.assertEqual(list(c), range(2,2000)) # test values of n self.assertRaises(TypeError, tee, 'abc', 'invalid') self.assertRaises(ValueError, tee, [], -1) for n in xrange(5): result = tee('abc', n) self.assertEqual(type(result), tuple) self.assertEqual(len(result), n) self.assertEqual(map(list, result), [list('abc')]*n) # tee pass-through to copyable iterator a, b = tee('abc') c, d = tee(a) self.assertTrue(a is c) # test tee_new t1, t2 = tee('abc') tnew = type(t1) self.assertRaises(TypeError, tnew) self.assertRaises(TypeError, tnew, 10) t3 = tnew(t1) self.assertTrue(list(t1) == list(t2) == list(t3) == list('abc')) # test that tee objects are weak referencable a, b = tee(xrange(10)) p = proxy(a) self.assertEqual(getattr(p, '__class__'), type(b)) del a self.assertRaises(ReferenceError, getattr, p, '__class__') def test_StopIteration(self): self.assertRaises(StopIteration, izip().next) for f in (chain, cycle, izip, groupby): self.assertRaises(StopIteration, f([]).next) self.assertRaises(StopIteration, f(StopNow()).next) self.assertRaises(StopIteration, islice([], None).next) self.assertRaises(StopIteration, islice(StopNow(), None).next) p, q = tee([]) self.assertRaises(StopIteration, p.next) self.assertRaises(StopIteration, q.next) p, q = tee(StopNow()) self.assertRaises(StopIteration, p.next) self.assertRaises(StopIteration, q.next) self.assertRaises(StopIteration, repeat(None, 0).next) for f in (ifilter, ifilterfalse, imap, takewhile, dropwhile, starmap): self.assertRaises(StopIteration, f(lambda x:x, []).next) self.assertRaises(StopIteration, f(lambda x:x, StopNow()).next) class TestExamples(unittest.TestCase): def test_chain(self): self.assertEqual(''.join(chain('ABC', 'DEF')), 'ABCDEF') def test_chain_from_iterable(self): self.assertEqual(''.join(chain.from_iterable(['ABC', 'DEF'])), 'ABCDEF') def test_combinations(self): self.assertEqual(list(combinations('ABCD', 2)), [('A','B'), ('A','C'), ('A','D'), ('B','C'), ('B','D'), ('C','D')]) self.assertEqual(list(combinations(range(4), 3)), [(0,1,2), (0,1,3), (0,2,3), (1,2,3)]) def test_combinations_with_replacement(self): self.assertEqual(list(combinations_with_replacement('ABC', 2)), [('A','A'), ('A','B'), ('A','C'), ('B','B'), ('B','C'), ('C','C')]) def test_compress(self): self.assertEqual(list(compress('ABCDEF', [1,0,1,0,1,1])), list('ACEF')) def test_count(self): self.assertEqual(list(islice(count(10), 5)), [10, 11, 12, 13, 14]) def test_cycle(self): self.assertEqual(list(islice(cycle('ABCD'), 12)), list('ABCDABCDABCD')) def test_dropwhile(self): self.assertEqual(list(dropwhile(lambda x: x<5, [1,4,6,4,1])), [6,4,1]) def test_groupby(self): self.assertEqual([k for k, g in groupby('AAAABBBCCDAABBB')], list('ABCDAB')) self.assertEqual([(list(g)) for k, g in groupby('AAAABBBCCD')], [list('AAAA'), list('BBB'), list('CC'), list('D')]) def test_ifilter(self): self.assertEqual(list(ifilter(lambda x: x%2, range(10))), [1,3,5,7,9]) def test_ifilterfalse(self): self.assertEqual(list(ifilterfalse(lambda x: x%2, range(10))), [0,2,4,6,8]) def test_imap(self): self.assertEqual(list(imap(pow, (2,3,10), (5,2,3))), [32, 9, 1000]) def test_islice(self): self.assertEqual(list(islice('ABCDEFG', 2)), list('AB')) self.assertEqual(list(islice('ABCDEFG', 2, 4)), list('CD')) self.assertEqual(list(islice('ABCDEFG', 2, None)), list('CDEFG')) self.assertEqual(list(islice('ABCDEFG', 0, None, 2)), list('ACEG')) def test_izip(self): self.assertEqual(list(izip('ABCD', 'xy')), [('A', 'x'), ('B', 'y')]) def test_izip_longest(self): self.assertEqual(list(izip_longest('ABCD', 'xy', fillvalue='-')), [('A', 'x'), ('B', 'y'), ('C', '-'), ('D', '-')]) def test_permutations(self): self.assertEqual(list(permutations('ABCD', 2)), map(tuple, 'AB AC AD BA BC BD CA CB CD DA DB DC'.split())) self.assertEqual(list(permutations(range(3))), [(0,1,2), (0,2,1), (1,0,2), (1,2,0), (2,0,1), (2,1,0)]) def test_product(self): self.assertEqual(list(product('ABCD', 'xy')), map(tuple, 'Ax Ay Bx By Cx Cy Dx Dy'.split())) self.assertEqual(list(product(range(2), repeat=3)), [(0,0,0), (0,0,1), (0,1,0), (0,1,1), (1,0,0), (1,0,1), (1,1,0), (1,1,1)]) def test_repeat(self): self.assertEqual(list(repeat(10, 3)), [10, 10, 10]) def test_stapmap(self): self.assertEqual(list(starmap(pow, [(2,5), (3,2), (10,3)])), [32, 9, 1000]) def test_takewhile(self): self.assertEqual(list(takewhile(lambda x: x<5, [1,4,6,4,1])), [1,4]) class TestGC(unittest.TestCase): def makecycle(self, iterator, container): container.append(iterator) iterator.next() del container, iterator def test_chain(self): a = [] self.makecycle(chain(a), a) def test_chain_from_iterable(self): a = [] self.makecycle(chain.from_iterable([a]), a) def test_combinations(self): a = [] self.makecycle(combinations([1,2,a,3], 3), a) def test_combinations_with_replacement(self): a = [] self.makecycle(combinations_with_replacement([1,2,a,3], 3), a) def test_compress(self): a = [] self.makecycle(compress('ABCDEF', [1,0,1,0,1,0]), a) def test_count(self): a = [] Int = type('Int', (int,), dict(x=a)) self.makecycle(count(Int(0), Int(1)), a) def test_cycle(self): a = [] self.makecycle(cycle([a]*2), a) def test_dropwhile(self): a = [] self.makecycle(dropwhile(bool, [0, a, a]), a) def test_groupby(self): a = [] self.makecycle(groupby([a]*2, lambda x:x), a) def test_issue2246(self): # Issue 2246 -- the _grouper iterator was not included in GC n = 10 keyfunc = lambda x: x for i, j in groupby(xrange(n), key=keyfunc): keyfunc.__dict__.setdefault('x',[]).append(j) def test_ifilter(self): a = [] self.makecycle(ifilter(lambda x:True, [a]*2), a) def test_ifilterfalse(self): a = [] self.makecycle(ifilterfalse(lambda x:False, a), a) def test_izip(self): a = [] self.makecycle(izip([a]*2, [a]*3), a) def test_izip_longest(self): a = [] self.makecycle(izip_longest([a]*2, [a]*3), a) b = [a, None] self.makecycle(izip_longest([a]*2, [a]*3, fillvalue=b), a) def test_imap(self): a = [] self.makecycle(imap(lambda x:x, [a]*2), a) def test_islice(self): a = [] self.makecycle(islice([a]*2, None), a) def test_permutations(self): a = [] self.makecycle(permutations([1,2,a,3], 3), a) def test_product(self): a = [] self.makecycle(product([1,2,a,3], repeat=3), a) def test_repeat(self): a = [] self.makecycle(repeat(a), a) def test_starmap(self): a = [] self.makecycle(starmap(lambda *t: t, [(a,a)]*2), a) def test_takewhile(self): a = [] self.makecycle(takewhile(bool, [1, 0, a, a]), a) def R(seqn): 'Regular generator' for i in seqn: yield i class G: 'Sequence using __getitem__' def __init__(self, seqn): self.seqn = seqn def __getitem__(self, i): return self.seqn[i] class I: 'Sequence using iterator protocol' def __init__(self, seqn): self.seqn = seqn self.i = 0 def __iter__(self): return self def next(self): if self.i >= len(self.seqn): raise StopIteration v = self.seqn[self.i] self.i += 1 return v class Ig: 'Sequence using iterator protocol defined with a generator' def __init__(self, seqn): self.seqn = seqn self.i = 0 def __iter__(self): for val in self.seqn: yield val class X: 'Missing __getitem__ and __iter__' def __init__(self, seqn): self.seqn = seqn self.i = 0 def next(self): if self.i >= len(self.seqn): raise StopIteration v = self.seqn[self.i] self.i += 1 return v class N: 'Iterator missing next()' def __init__(self, seqn): self.seqn = seqn self.i = 0 def __iter__(self): return self class E: 'Test propagation of exceptions' def __init__(self, seqn): self.seqn = seqn self.i = 0 def __iter__(self): return self def next(self): 3 // 0 class S: 'Test immediate stop' def __init__(self, seqn): pass def __iter__(self): return self def next(self): raise StopIteration def L(seqn): 'Test multiple tiers of iterators' return chain(imap(lambda x:x, R(Ig(G(seqn))))) class TestVariousIteratorArgs(unittest.TestCase): def test_chain(self): for s in ("123", "", range(1000), ('do', 1.2), xrange(2000,2200,5)): for g in (G, I, Ig, S, L, R): self.assertEqual(list(chain(g(s))), list(g(s))) self.assertEqual(list(chain(g(s), g(s))), list(g(s))+list(g(s))) self.assertRaises(TypeError, list, chain(X(s))) self.assertRaises(TypeError, list, chain(N(s))) self.assertRaises(ZeroDivisionError, list, chain(E(s))) def test_compress(self): for s in ("123", "", range(1000), ('do', 1.2), xrange(2000,2200,5)): n = len(s) for g in (G, I, Ig, S, L, R): self.assertEqual(list(compress(g(s), repeat(1))), list(g(s))) self.assertRaises(TypeError, compress, X(s), repeat(1)) self.assertRaises(TypeError, list, compress(N(s), repeat(1))) self.assertRaises(ZeroDivisionError, list, compress(E(s), repeat(1))) def test_product(self): for s in ("123", "", range(1000), ('do', 1.2), xrange(2000,2200,5)): self.assertRaises(TypeError, product, X(s)) self.assertRaises(TypeError, product, N(s)) self.assertRaises(ZeroDivisionError, product, E(s)) def test_cycle(self): for s in ("123", "", range(1000), ('do', 1.2), xrange(2000,2200,5)): for g in (G, I, Ig, S, L, R): tgtlen = len(s) * 3 expected = list(g(s))*3 actual = list(islice(cycle(g(s)), tgtlen)) self.assertEqual(actual, expected) self.assertRaises(TypeError, cycle, X(s)) self.assertRaises(TypeError, list, cycle(N(s))) self.assertRaises(ZeroDivisionError, list, cycle(E(s))) def test_groupby(self): for s in (range(10), range(0), range(1000), (7,11), xrange(2000,2200,5)): for g in (G, I, Ig, S, L, R): self.assertEqual([k for k, sb in groupby(g(s))], list(g(s))) self.assertRaises(TypeError, groupby, X(s)) self.assertRaises(TypeError, list, groupby(N(s))) self.assertRaises(ZeroDivisionError, list, groupby(E(s))) def test_ifilter(self): for s in (range(10), range(0), range(1000), (7,11), xrange(2000,2200,5)): for g in (G, I, Ig, S, L, R): self.assertEqual(list(ifilter(isEven, g(s))), filter(isEven, g(s))) self.assertRaises(TypeError, ifilter, isEven, X(s)) self.assertRaises(TypeError, list, ifilter(isEven, N(s))) self.assertRaises(ZeroDivisionError, list, ifilter(isEven, E(s))) def test_ifilterfalse(self): for s in (range(10), range(0), range(1000), (7,11), xrange(2000,2200,5)): for g in (G, I, Ig, S, L, R): self.assertEqual(list(ifilterfalse(isEven, g(s))), filter(isOdd, g(s))) self.assertRaises(TypeError, ifilterfalse, isEven, X(s)) self.assertRaises(TypeError, list, ifilterfalse(isEven, N(s))) self.assertRaises(ZeroDivisionError, list, ifilterfalse(isEven, E(s))) def test_izip(self): for s in ("123", "", range(1000), ('do', 1.2), xrange(2000,2200,5)): for g in (G, I, Ig, S, L, R): self.assertEqual(list(izip(g(s))), zip(g(s))) self.assertEqual(list(izip(g(s), g(s))), zip(g(s), g(s))) self.assertRaises(TypeError, izip, X(s)) self.assertRaises(TypeError, list, izip(N(s))) self.assertRaises(ZeroDivisionError, list, izip(E(s))) def test_iziplongest(self): for s in ("123", "", range(1000), ('do', 1.2), xrange(2000,2200,5)): for g in (G, I, Ig, S, L, R): self.assertEqual(list(izip_longest(g(s))), zip(g(s))) self.assertEqual(list(izip_longest(g(s), g(s))), zip(g(s), g(s))) self.assertRaises(TypeError, izip_longest, X(s)) self.assertRaises(TypeError, list, izip_longest(N(s))) self.assertRaises(ZeroDivisionError, list, izip_longest(E(s))) def test_imap(self): for s in (range(10), range(0), range(100), (7,11), xrange(20,50,5)): for g in (G, I, Ig, S, L, R): self.assertEqual(list(imap(onearg, g(s))), map(onearg, g(s))) self.assertEqual(list(imap(operator.pow, g(s), g(s))), map(operator.pow, g(s), g(s))) self.assertRaises(TypeError, imap, onearg, X(s)) self.assertRaises(TypeError, list, imap(onearg, N(s))) self.assertRaises(ZeroDivisionError, list, imap(onearg, E(s))) def test_islice(self): for s in ("12345", "", range(1000), ('do', 1.2), xrange(2000,2200,5)): for g in (G, I, Ig, S, L, R): self.assertEqual(list(islice(g(s),1,None,2)), list(g(s))[1::2]) self.assertRaises(TypeError, islice, X(s), 10) self.assertRaises(TypeError, list, islice(N(s), 10)) self.assertRaises(ZeroDivisionError, list, islice(E(s), 10)) def test_starmap(self): for s in (range(10), range(0), range(100), (7,11), xrange(20,50,5)): for g in (G, I, Ig, S, L, R): ss = zip(s, s) self.assertEqual(list(starmap(operator.pow, g(ss))), map(operator.pow, g(s), g(s))) self.assertRaises(TypeError, starmap, operator.pow, X(ss)) self.assertRaises(TypeError, list, starmap(operator.pow, N(ss))) self.assertRaises(ZeroDivisionError, list, starmap(operator.pow, E(ss))) def test_takewhile(self): for s in (range(10), range(0), range(1000), (7,11), xrange(2000,2200,5)): for g in (G, I, Ig, S, L, R): tgt = [] for elem in g(s): if not isEven(elem): break tgt.append(elem) self.assertEqual(list(takewhile(isEven, g(s))), tgt) self.assertRaises(TypeError, takewhile, isEven, X(s)) self.assertRaises(TypeError, list, takewhile(isEven, N(s))) self.assertRaises(ZeroDivisionError, list, takewhile(isEven, E(s))) def test_dropwhile(self): for s in (range(10), range(0), range(1000), (7,11), xrange(2000,2200,5)): for g in (G, I, Ig, S, L, R): tgt = [] for elem in g(s): if not tgt and isOdd(elem): continue tgt.append(elem) self.assertEqual(list(dropwhile(isOdd, g(s))), tgt) self.assertRaises(TypeError, dropwhile, isOdd, X(s)) self.assertRaises(TypeError, list, dropwhile(isOdd, N(s))) self.assertRaises(ZeroDivisionError, list, dropwhile(isOdd, E(s))) def test_tee(self): for s in ("123", "", range(1000), ('do', 1.2), xrange(2000,2200,5)): for g in (G, I, Ig, S, L, R): it1, it2 = tee(g(s)) self.assertEqual(list(it1), list(g(s))) self.assertEqual(list(it2), list(g(s))) self.assertRaises(TypeError, tee, X(s)) self.assertRaises(TypeError, list, tee(N(s))[0]) self.assertRaises(ZeroDivisionError, list, tee(E(s))[0]) class LengthTransparency(unittest.TestCase): def test_repeat(self): from test.test_iterlen import len self.assertEqual(len(repeat(None, 50)), 50) self.assertRaises(TypeError, len, repeat(None)) class RegressionTests(unittest.TestCase): def test_sf_793826(self): # Fix Armin Rigo's successful efforts to wreak havoc def mutatingtuple(tuple1, f, tuple2): # this builds a tuple t which is a copy of tuple1, # then calls f(t), then mutates t to be equal to tuple2 # (needs len(tuple1) == len(tuple2)). def g(value, first=[1]): if first: del first[:] f(z.next()) return value items = list(tuple2) items[1:1] = list(tuple1) gen = imap(g, items) z = izip(*[gen]*len(tuple1)) z.next() def f(t): global T T = t first[:] = list(T) first = [] mutatingtuple((1,2,3), f, (4,5,6)) second = list(T) self.assertEqual(first, second) def test_sf_950057(self): # Make sure that chain() and cycle() catch exceptions immediately # rather than when shifting between input sources def gen1(): hist.append(0) yield 1 hist.append(1) raise AssertionError hist.append(2) def gen2(x): hist.append(3) yield 2 hist.append(4) if x: raise StopIteration hist = [] self.assertRaises(AssertionError, list, chain(gen1(), gen2(False))) self.assertEqual(hist, [0,1]) hist = [] self.assertRaises(AssertionError, list, chain(gen1(), gen2(True))) self.assertEqual(hist, [0,1]) hist = [] self.assertRaises(AssertionError, list, cycle(gen1())) self.assertEqual(hist, [0,1]) class SubclassWithKwargsTest(unittest.TestCase): def test_keywords_in_subclass(self): # count is not subclassable... for cls in (repeat, izip, ifilter, ifilterfalse, chain, imap, starmap, islice, takewhile, dropwhile, cycle, compress): class Subclass(cls): def __init__(self, newarg=None, *args): cls.__init__(self, *args) try: Subclass(newarg=1) except TypeError, err: # we expect type errors because of wrong argument count self.assertFalse("does not take keyword arguments" in err.args[0]) libreftest = """ Doctest for examples in the library reference: libitertools.tex >>> amounts = [120.15, 764.05, 823.14] >>> for checknum, amount in izip(count(1200), amounts): ... print 'Check %d is for $%.2f' % (checknum, amount) ... Check 1200 is for $120.15 Check 1201 is for $764.05 Check 1202 is for $823.14 >>> import operator >>> for cube in imap(operator.pow, xrange(1,4), repeat(3)): ... print cube ... 1 8 27 >>> reportlines = ['EuroPython', 'Roster', '', 'alex', '', 'laura', '', 'martin', '', 'walter', '', 'samuele'] >>> for name in islice(reportlines, 3, None, 2): ... print name.title() ... Alex Laura Martin Walter Samuele >>> from operator import itemgetter >>> d = dict(a=1, b=2, c=1, d=2, e=1, f=2, g=3) >>> di = sorted(sorted(d.iteritems()), key=itemgetter(1)) >>> for k, g in groupby(di, itemgetter(1)): ... print k, map(itemgetter(0), g) ... 1 ['a', 'c', 'e'] 2 ['b', 'd', 'f'] 3 ['g'] # Find runs of consecutive numbers using groupby. The key to the solution # is differencing with a range so that consecutive numbers all appear in # same group. >>> data = [ 1, 4,5,6, 10, 15,16,17,18, 22, 25,26,27,28] >>> for k, g in groupby(enumerate(data), lambda (i,x):i-x): ... print map(operator.itemgetter(1), g) ... [1] [4, 5, 6] [10] [15, 16, 17, 18] [22] [25, 26, 27, 28] >>> def take(n, iterable): ... "Return first n items of the iterable as a list" ... return list(islice(iterable, n)) >>> def enumerate(iterable, start=0): ... return izip(count(start), iterable) >>> def tabulate(function, start=0): ... "Return function(0), function(1), ..." ... return imap(function, count(start)) >>> def nth(iterable, n, default=None): ... "Returns the nth item or a default value" ... return next(islice(iterable, n, None), default) >>> def quantify(iterable, pred=bool): ... "Count how many times the predicate is true" ... return sum(imap(pred, iterable)) >>> def padnone(iterable): ... "Returns the sequence elements and then returns None indefinitely" ... return chain(iterable, repeat(None)) >>> def ncycles(iterable, n): ... "Returns the seqeuence elements n times" ... return chain(*repeat(iterable, n)) >>> def dotproduct(vec1, vec2): ... return sum(imap(operator.mul, vec1, vec2)) >>> def flatten(listOfLists): ... return list(chain.from_iterable(listOfLists)) >>> def repeatfunc(func, times=None, *args): ... "Repeat calls to func with specified arguments." ... " Example: repeatfunc(random.random)" ... if times is None: ... return starmap(func, repeat(args)) ... else: ... return starmap(func, repeat(args, times)) >>> def pairwise(iterable): ... "s -> (s0,s1), (s1,s2), (s2, s3), ..." ... a, b = tee(iterable) ... for elem in b: ... break ... return izip(a, b) >>> def grouper(n, iterable, fillvalue=None): ... "grouper(3, 'ABCDEFG', 'x') --> ABC DEF Gxx" ... args = [iter(iterable)] * n ... return izip_longest(fillvalue=fillvalue, *args) >>> def roundrobin(*iterables): ... "roundrobin('ABC', 'D', 'EF') --> A D E B F C" ... # Recipe credited to George Sakkis ... pending = len(iterables) ... nexts = cycle(iter(it).next for it in iterables) ... while pending: ... try: ... for next in nexts: ... yield next() ... except StopIteration: ... pending -= 1 ... nexts = cycle(islice(nexts, pending)) >>> def powerset(iterable): ... "powerset([1,2,3]) --> () (1,) (2,) (3,) (1,2) (1,3) (2,3) (1,2,3)" ... s = list(iterable) ... return chain.from_iterable(combinations(s, r) for r in range(len(s)+1)) >>> def unique_everseen(iterable, key=None): ... "List unique elements, preserving order. Remember all elements ever seen." ... # unique_everseen('AAAABBBCCDAABBB') --> A B C D ... # unique_everseen('ABBCcAD', str.lower) --> A B C D ... seen = set() ... seen_add = seen.add ... if key is None: ... for element in iterable: ... if element not in seen: ... seen_add(element) ... yield element ... else: ... for element in iterable: ... k = key(element) ... if k not in seen: ... seen_add(k) ... yield element >>> def unique_justseen(iterable, key=None): ... "List unique elements, preserving order. Remember only the element just seen." ... # unique_justseen('AAAABBBCCDAABBB') --> A B C D A B ... # unique_justseen('ABBCcAD', str.lower) --> A B C A D ... return imap(next, imap(itemgetter(1), groupby(iterable, key))) This is not part of the examples but it tests to make sure the definitions perform as purported. >>> take(10, count()) [0, 1, 2, 3, 4, 5, 6, 7, 8, 9] >>> list(enumerate('abc')) [(0, 'a'), (1, 'b'), (2, 'c')] >>> list(islice(tabulate(lambda x: 2*x), 4)) [0, 2, 4, 6] >>> nth('abcde', 3) 'd' >>> nth('abcde', 9) is None True >>> quantify(xrange(99), lambda x: x%2==0) 50 >>> a = [[1, 2, 3], [4, 5, 6]] >>> flatten(a) [1, 2, 3, 4, 5, 6] >>> list(repeatfunc(pow, 5, 2, 3)) [8, 8, 8, 8, 8] >>> import random >>> take(5, imap(int, repeatfunc(random.random))) [0, 0, 0, 0, 0] >>> list(pairwise('abcd')) [('a', 'b'), ('b', 'c'), ('c', 'd')] >>> list(pairwise([])) [] >>> list(pairwise('a')) [] >>> list(islice(padnone('abc'), 0, 6)) ['a', 'b', 'c', None, None, None] >>> list(ncycles('abc', 3)) ['a', 'b', 'c', 'a', 'b', 'c', 'a', 'b', 'c'] >>> dotproduct([1,2,3], [4,5,6]) 32 >>> list(grouper(3, 'abcdefg', 'x')) [('a', 'b', 'c'), ('d', 'e', 'f'), ('g', 'x', 'x')] >>> list(roundrobin('abc', 'd', 'ef')) ['a', 'd', 'e', 'b', 'f', 'c'] >>> list(powerset([1,2,3])) [(), (1,), (2,), (3,), (1, 2), (1, 3), (2, 3), (1, 2, 3)] >>> all(len(list(powerset(range(n)))) == 2**n for n in range(18)) True >>> list(powerset('abcde')) == sorted(sorted(set(powerset('abcde'))), key=len) True >>> list(unique_everseen('AAAABBBCCDAABBB')) ['A', 'B', 'C', 'D'] >>> list(unique_everseen('ABBCcAD', str.lower)) ['A', 'B', 'C', 'D'] >>> list(unique_justseen('AAAABBBCCDAABBB')) ['A', 'B', 'C', 'D', 'A', 'B'] >>> list(unique_justseen('ABBCcAD', str.lower)) ['A', 'B', 'C', 'A', 'D'] """ __test__ = {'libreftest' : libreftest} def test_main(verbose=None): test_classes = (TestBasicOps, TestVariousIteratorArgs, TestGC, RegressionTests, LengthTransparency, SubclassWithKwargsTest, TestExamples) test_support.run_unittest(*test_classes) # verify reference counting if verbose and hasattr(sys, "gettotalrefcount"): import gc counts = [None] * 5 for i in xrange(len(counts)): test_support.run_unittest(*test_classes) gc.collect() counts[i] = sys.gettotalrefcount() print counts # doctest the examples in the library reference test_support.run_doctest(sys.modules[__name__], verbose) if __name__ == "__main__": test_main(verbose=True)