def test_15(self):
data = range(1, 10)
_mult = Stream(data).collect(Reduce(bi_func=op.mul))
self.assertTrue(_mult.present())
self.assertEqual(_mult.get(), factorial(9))
def test_14(self):
data = range(10)
_sum = Stream(data).collect(Reduce(bi_func=op.add))
self.assertTrue(_sum.present())
self.assertEqual(_sum.get(), sum(data))
def test_cycle(self):
out = Stream([4, 1, 2, 3, 9, 0, 5]).cycle(range(3)).collect(ToList())
self.assertListEqual(out, [(4, 0), (1, 1), (2, 2), (3, 0), (9, 1),
(0, 2), (5, 0)])
out = Stream([4, 1, 2, 3, 9, 0,
5]).cycle(range(3), after=False).collect(ToList())
self.assertListEqual(out, [(0, 4), (1, 1), (2, 2), (0, 3), (1, 9),
(2, 0), (0, 5)])
def test_map2(self):
rnd = self.rnd
a, b, size = 1, 100, 1000
add_5 = lambda x: x + 5
pow_3 = lambda x: x**3
mod_2_not_zero = lambda x: x % 2 != 0
mod_3_not_2 = lambda x: x % 3 != 2
mod_5_not_4 = lambda x: x % 5 != 4
out = (Stream(rnd.int_range_supplier(
a, b)).limit(size).filter(mod_3_not_2).map(add_5).filter(
mod_2_not_zero).map(pow_3).filter(mod_5_not_4).collect(
ToList()))
rnd.reset()
out_target = []
for e in rnd.int_range(a, b, size=size):
if mod_3_not_2(e):
e = add_5(e)
if mod_2_not_zero(e):
e = pow_3(e)
if mod_5_not_4(e):
out_target.append(e)
self.assertListEqual(out, out_target)
def test_4(self):
size = 10
eps = 1e-9
class Data:
def __init__(self, e):
self._e = e
def e(self):
return self._e
def __eq__(self, other) -> bool:
return abs(self._e - other._e) <= eps
rnd = random()
out = (Stream.from_supplier(rnd.random).limit(size).map(Data).sort(
key=Data.e, reverse=True).collect(ToList()))
rnd.reset()
out_target = sorted((Data(rnd.random()) for _ in range(size)),
key=Data.e,
reverse=True)
for o, t in zip(out, out_target):
with self.subTest(o=o):
self.assertAlmostEqual(o, t)
def test_10(self):
data = [1, 3, 1]
def square(x):
return x * x
# Value Error will be thrown, because number '1' is present multiple times.
# and we have not provided any "merger_on_conflict".
Stream(data).collect(ToMap(identity, square))
def test_9(self):
data = range(10)
def square(x):
return x * x
out = Stream(data).collect(ToMap(identity, square))
out_target = {e: square(e) for e in data}
self.assertDictEqual(out, out_target)
def test_11(self):
data = [1, 3, 1]
def square(x):
return x * x
out = Stream(data).collect(
ToMap(identity, square, merger_on_conflict=on_conflict_do_nothing))
out_target = {1: 1, 3: 9}
self.assertDictEqual(out, out_target)
def test_1a(self):
rnd = random()
start, end = 1, 100
size = 1000
data = rnd.int_range(start, end, size=size)
element_frequency = Stream(data).collect(
GroupingBy(identity, Counting()))
out_target = Counter(data)
self.assertDictEqual(element_frequency, out_target)
def test_map3(self):
rnd = self.rnd
a, b, size = 1, 100, 1000
pow_2 = lambda x: x**2
out = sum(Stream(rnd.int_range_supplier(a, b)).limit(size).map(pow_2))
rnd.reset()
out_target = sum(pow_2(e) for e in rnd.int_range(a, b, size=size))
self.assertEqual(out, out_target)
def test_map5(self):
rnd = self.rnd
a, b, size = 1, 100, 50
out = Stream(rnd.int_range_supplier(a, b)) \
.limit(size) \
.reduce(1, bi_func=op.mul) \
.get()
rnd.reset()
out_target = reduce(op.mul, rnd.int_range(a, b, size=size))
self.assertEqual(out, out_target)
def test_map1(self):
rnd = self.rnd
a, b, size = 1, 100, 1000
add_5 = lambda x: x + 5
pow_3 = lambda x: x**3
out = (Stream(rnd.int_range_supplier(
a, b)).limit(size).map(add_5).map(pow_3).collect(ToList()))
rnd.reset()
out_target = [pow_3(add_5(e)) for e in rnd.int_range(a, b, size=size)]
self.assertListEqual(out, out_target)
def test_1(self):
rnd = random()
start, end = 1, 100
size = 1000
data = rnd.int_range(start, end, size=size)
# finding frequency of integer numbers generated by random source "rnd".
# To get this, grouping by elements on their value then collecting them in a list
# and then finding number of elements in list.
# For better method see "test_1a"
element_frequency = Stream(data).collect(
GroupingBy(identity, CollectAndThen(ToList(), len)))
out_target = Counter(data)
self.assertDictEqual(element_frequency, out_target)
def test_map4(self):
rnd = self.rnd
a, b, size = 1, 100, 1000
pow_2 = lambda x: x**2
out = Stream(rnd.int_range_supplier(a, b)) \
.limit(size) \
.map(pow_2) \
.reduce(0, bi_func=op.add) \
.get()
rnd.reset()
out_target = sum(pow_2(e) for e in rnd.int_range(a, b, size=size))
self.assertEqual(out, out_target)
def test_map8(self):
rnd = self.rnd
a, b, size = 1, 100, 50
rng = range(3, 70)
out = (Stream(rnd.int_range_supplier(
a, b)).limit(size).zip(rng).map(sum).reduce(1,
bi_func=op.mul).get())
rnd.reset()
data = (e + r for e, r in zip(rnd.int_range(a, b, size=size), rng))
out_target = reduce(op.mul, data)
self.assertEqual(out, out_target)
def test_2(self):
size = 1000
rnd = random()
square = lambda x: x**2
out = (Stream.from_supplier(rnd.random).limit(size).map(square).sort(
reverse=True).collect(ToList()))
rnd.reset()
out_target = sorted((square(rnd.random()) for _ in range(size)),
reverse=True)
for o, t in zip(out, out_target):
with self.subTest(o=o):
self.assertAlmostEqual(o, t, delta=1e-9)
