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 | |
import copy | |
import pickle | |
from functools import reduce | |
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.assertEqual(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.assertEqual(len(prod), n**r) | |
self.assertEqual(len(cwr), (fact(n+r-1) // fact(r) // fact(n-1)) if n else (not r)) | |
self.assertEqual(len(perm), 0 if r>n else fact(n) // fact(n-r)) | |
self.assertEqual(len(comb), 0 if r>n else fact(n) // fact(r) // fact(n-r)) | |
# Check lexicographic order without repeated tuples | |
self.assertEqual(prod, sorted(set(prod))) | |
self.assertEqual(cwr, sorted(set(cwr))) | |
self.assertEqual(perm, sorted(set(perm))) | |
self.assertEqual(comb, sorted(set(comb))) | |
# Check interrelationships | |
self.assertEqual(cwr, [t for t in prod if sorted(t)==list(t)]) # cwr: prods which are sorted | |
self.assertEqual(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) | |
# check copy, deepcopy, pickle | |
for value in -3, 3, sys.maxint-5, sys.maxint+5: | |
c = count(value) | |
self.assertEqual(next(copy.copy(c)), value) | |
self.assertEqual(next(copy.deepcopy(c)), value) | |
self.assertEqual(next(pickle.loads(pickle.dumps(c))), value) | |
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) <- this raises a py3k warning | |
# this is the replacement: | |
target = [tuple([arg[i] if i < len(arg) else None for arg in args]) | |
for i in range(max(map(len, 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', **{})), | |
zip(list('abc') + [None], '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_bug_7244(self): | |
class Repeater(object): | |
# this class is similar to itertools.repeat | |
def __init__(self, o, t, e): | |
self.o = o | |
self.t = int(t) | |
self.e = e | |
def __iter__(self): # its iterator is itself | |
return self | |
def next(self): | |
if self.t > 0: | |
self.t -= 1 | |
return self.o | |
else: | |
raise self.e | |
# Formerly this code in would fail in debug mode | |
# with Undetected Error and Stop Iteration | |
r1 = Repeater(1, 3, StopIteration) | |
r2 = Repeater(2, 4, StopIteration) | |
def run(r1, r2): | |
result = [] | |
for i, j in izip_longest(r1, r2, fillvalue=0): | |
with test_support.captured_output('stdout'): | |
print (i, j) | |
result.append((i, j)) | |
return result | |
self.assertEqual(run(r1, r2), [(1,2), (1,2), (1,2), (0,2)]) | |
# Formerly, the RuntimeError would be lost | |
# and StopIteration would stop as expected | |
r1 = Repeater(1, 3, RuntimeError) | |
r2 = Repeater(2, 4, StopIteration) | |
it = izip_longest(r1, r2, fillvalue=0) | |
self.assertEqual(next(it), (1, 2)) | |
self.assertEqual(next(it), (1, 2)) | |
self.assertEqual(next(it), (1, 2)) | |
self.assertRaises(RuntimeError, next, it) | |
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) | |
# Issue #10323: Less islice in a predictable state | |
c = count() | |
self.assertEqual(list(islice(c, 1, 3, 50)), [1]) | |
self.assertEqual(next(c), 3) | |
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.assertNotIn("does not take keyword arguments", 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 t:t[0]-t[1]): | |
... 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 sequence 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) |