def testExtend(self):
s = Stream.number().filter(lambda i: i % 3 == 0).take(3).extend(
Stream.number().filter(lambda i: i % 3 == 1).take(3),
Stream.number().filter(lambda i: i % 3 == 2).take(3))
l = s.to_list()
self.assertEqual(9, len(l))
self.assertEqual(8, l[-1])
def testAnyAll(self):
self.assertFalse(
Stream.number(step=2).take(10).any(lambda x: x % 2 != 0))
self.assertTrue(
Stream.number(step=2).take(10).all(lambda x: x % 2 == 0))
self.assertFalse(Stream.empty().any(lambda x: x > 0))
self.assertTrue(Stream.empty().all(lambda x: x > 0))
def testTakeWhile(self):
self.assertEqual(
8,
self.countIter(Stream.number(step=2).take_while(lambda i: i < 15)))
self.assertEqual(
14, max(Stream.number(step=2).take_while(lambda i: i < 15)))
self.assertEqual(
0, max(Stream.number(step=2).take_while(lambda i: i < 1)))
def testForeach(self):
count = {"count": 0}
def addCount(x):
count["count"] += x
Stream.number().map(lambda x: x**2).filter(lambda x: x % 3 == 0).take(
3).foreach(lambda x: addCount(x))
self.assertEqual(45, count["count"])
def testConcat(self):
l = Stream.concat(
Stream.number().filter(lambda i: i % 3 == 0).take(3),
Stream.number().filter(lambda i: i % 3 == 1).take(3),
Stream.number().filter(lambda i: i % 3 == 2).take(3)).to_list()
self.assertEqual(9, len(l))
self.assertEqual(8, l[-1])
l = Stream.concat(Stream.number().filter(lambda i: i % 3 == 0).take(3),
range(3)).to_list()
self.assertEqual(6, len(l))
def testFold(self):
self.assertEqual(45,
Stream.number().take(10).fold(lambda x, y: x + y, 0))
self.assertEqual(
"01234",
Stream.number().take(5).fold(lambda x, y: x + str(y), ""))
self.assertTrue(45, Stream.number().take(10).sum())
self.assertEqual(
"01234",
Stream.number().take(5).map(lambda i: str(i)).join(""))
def testZip(self):
l = Stream.zip(range(5),
Stream.number(start=4, step=-1).take(8)).to_list()
self.assertEqual(5, len(l))
self.assertTrue(
Stream(l).map(lambda tup: tup[0] + tup[1]).all(lambda x: x == 4))
l = Stream.number(start=4,
step=-1).take(8).zip_with(range(5)).to_list()
self.assertEqual(5, len(l))
self.assertTrue(
Stream(l).map(lambda tup: tup[0] + tup[1]).all(lambda x: x == 4))
def testToMap(self):
m = Stream.zip(range(5),
Stream.number(start=4, step=-1).take(3)).to_map()
self.assertEqual(3, len(m))
self.assertEqual(4, m[0])
self.assertEqual(3, m[1])
self.assertEqual(2, m[2])
m = Stream.number().take(3).to_map(key=lambda it: it,
value=lambda it: it * 2)
self.assertEqual(2, m[1])
self.assertEqual(4, m[2])
self.assertEqual(0, m[0])
def testFilter(self):
self.assertEqual(
12, sum(Stream.number().filter(lambda i: i % 2 == 0).take(4)))
def testTake(self):
s = Stream.number(step=2)
self.assertEqual(4, self.countIter(s.take(4)))
self.assertEqual(0, self.countIter(s.take(0)))
self.assertEqual(3, self.countIter(s.take(3).take(4)))
def testInfinite(self):
s = Stream.number(step=2)
for i in range(100):
self.assertEqual(i * 2, s.next())
def testFlat(self):
l = Stream.number(
step=3).map(lambda x: (x, x + 1, x + 2)).flat().take(10).to_list()
self.assertEqual(45, sum(l))
def testprepend(self):
l = Stream.number().take(4).prepend(99, 100, 101).to_list()
self.assertEqual(7, len(l))
self.assertEqual(1, l[-3])
self.assertEqual(99, l[0])
def testAppend(self):
l = Stream.number().take(4).append(99, 100, 101).to_list()
self.assertEqual(7, len(l))
self.assertEqual(101, l[-1])
def testTolist(self):
self.assertEqual([1, 3, 5],
Stream.number(start=1, step=2).take(3).to_list())
def testNextItem(self):
self.assertEqual(3, Stream.number(start=3).next_item().get())
self.assertEqual(100, Stream.empty().next_item().or_else(100))
def testMap(self):
self.assertEqual(16, max(Stream.number().map(lambda x: x**2).take(5)))