def test_to():
assert Stream.range(5, 8).to_array() == Array([5, 6, 7])
assert Stream([(1, 2), (3, 4)]).to_dict() == {1: 2, 3: 4}
assert Stream.range(5, 8).to_set() == set([5, 6, 7])
assert list(Stream.range(5, 8)) == [5, 6, 7]
assert Stream.range(5, 8).to_series().equals(pd.Series([5, 6, 7]))
def test_filtering():
def is_even(n):
return n % 2 == 0
assert Stream.range(5, 10).filter(is_even).to_list() == [6, 8]
assert Stream.range(5, 10).filter_false(is_even).to_list() == [5, 7, 9]
assert Stream.range(5, 10).without(6, 8).to_list() == [5, 7, 9]
def test_slice():
assert Stream.range(5, 10).take(3).to_list() == [5, 6, 7]
assert Stream.range(5, 10).drop(3).to_list() == [8, 9]
def less_than_3(n):
return n < 3
assert Stream.range(0, 5).takewhile(less_than_3).to_list() == [0, 1, 2]
assert Stream.range(0, 5).dropwhile(less_than_3).to_list() == [3, 4]
def test_groupby():
assert (Stream.range(10).group_by_as_stream(lambda n: n // 3).starmap(
lambda k, vs: (k, list(vs))).to_list() == [(0, [0, 1, 2]),
(1, [3, 4, 5]),
(2, [6, 7, 8]), (3, [9])])
assert Stream.range(10).group_by_as_map(lambda n: n // 3) == {
0: Array([0, 1, 2]),
1: Array([3, 4, 5]),
2: Array([6, 7, 8]),
3: Array([9])
}
def test_map():
def multiply_2(n):
return n * 2
assert Stream.range(10).map(multiply_2).to_list() == list(range(0, 20, 2))
def duplicate(v):
return [v] * 2
assert Stream.range(3).flat_map(duplicate).to_list() == [0, 0, 1, 1, 2, 2]
assert Stream([(5, 1), (3, 4)]).flatten().to_list() == [5, 1, 3, 4]
assert Stream.range(10).len() == 10
assert Stream([(5, 1), (3, 4)]).flatten().len() == 4
def test_split():
def divisible_by_three(n):
return n % 3 == 0
assert Stream.range(10).split_before(divisible_by_three).to_list() == [
Array([0, 1, 2]),
Array([3, 4, 5]),
Array([6, 7, 8]),
Array([9])
]
assert Stream.range(10).split_after(divisible_by_three).to_list() == [
Array([0]),
Array([1, 2, 3]),
Array([4, 5, 6]),
Array([7, 8, 9])
]
def test_reduce():
assert Stream.range(5, 8).reduce(lambda a, b: a + b) == 18
assert Stream.range(5, 8).fold_left(lambda a, b: a + b, 2) == 20
assert Stream.range(5, 8).mean() == 6
assert Stream.range(5, 8).sum() == 18
assert Stream.range(5, 8).accumulate().to_list() == [5, 11, 18]
assert Stream.range(5, 8).accumulate(op.mul).to_list() == [5, 30, 210]
def test_zip():
assert Stream.range(5, 8).zip(itt.count(1)).to_list() == [(5, 1), (6, 2),
(7, 3)]
assert Stream.range(5, 8).zip(itt.count(1)).to_list() == [(5, 1), (6, 2),
(7, 3)]
assert Stream.range(5, 8).zip_longest(range(1, 5)).to_list() == [(5, 1),
(6, 2),
(7, 3),
(None, 4)]
assert (Stream.range(5,
8).zip_longest(range(1, 5),
fillvalue=100).to_list() == [(5, 1),
(6, 2),
(7, 3),
(100, 4)])
assert Stream.range(5, 8).zip_prev().to_list() == [
CurrPrev(5, None), CurrPrev(6, 5),
CurrPrev(7, 6)
]
assert Stream.range(5, 8).zip_next().to_list() == [
CurrNext(5, 6), CurrNext(6, 7),
CurrNext(7, None)
]
assert Stream.range(5, 8).zip_prev(99).to_list() == [
CurrPrev(5, 99), CurrPrev(6, 5),
CurrPrev(7, 6)
]
assert Stream.range(5, 8).zip_next(99).to_list() == [
CurrNext(5, 6), CurrNext(6, 7),
CurrNext(7, 99)
]
assert Stream.range(5, 8).zip_index().to_list() == [
ValueIndex(5, 0), ValueIndex(6, 1),
ValueIndex(7, 2)
]
def test_access():
assert Stream.range(5, 10).get(3) == 8
assert Stream.range(5, 10).get(5, 0) == 0
assert Stream.range(5, 10).get(7, 0) == 0
assert Stream.range(5, 10).get(6) is None
with pytest.raises(ValueError):
assert Stream.range(5, 10).get(-1) is None
assert Stream.range(5, 10)[3] == 8
with pytest.raises(ValueError):
assert Stream(iter(range(5, 10)))[-1]
with pytest.raises(IndexError):
assert Stream.range(5, 10)[5]
assert Stream.range(5, 10).get_opt(3) == Some(8)
assert Stream.range(5, 10).get_opt(5) is Nothing
with pytest.raises(ValueError):
assert Stream(iter(range(5, 10))).get_opt(-1) is Nothing
assert Stream.range(5, 10).first() == 5
assert Stream.range(5, 10).first_opt() == Some(5)
assert Stream([5]).first_opt() == Some(5)
assert Stream([]).first_opt() is Nothing
assert Stream(iter([])).first_opt() is Nothing
def test_init():
assert Stream([1, 2, 3]).to_list() == [1, 2, 3]
assert Stream(range(10)).to_list() == list(range(10))
assert Stream.range(10).to_list() == list(range(10))
def test_sliding_window():
assert Stream.range(5, 10).sliding_window(3).to_list() == [(5, 6, 7),
(6, 7, 8),
(7, 8, 9)]
def test_extend():
assert Stream.range(5, 8).extended([1, 3]).to_list() == [5, 6, 7, 1, 3]
assert Stream.range(5, 8).appended(5).to_list() == [5, 6, 7, 5]
def test_ordering():
assert Stream.range(5, 8).reversed().to_list() == [7, 6, 5]
assert Stream([1, 3, 2, 4]).sorted().to_list() == [1, 2, 3, 4]
assert Stream([1, 3, 2, 4]).sorted(lambda x: -x).to_list() == [4, 3, 2, 1]
assert Stream([1, 3, 2,
4]).sorted(lambda x: x % 2).to_list() == [2, 4, 1, 3]
def test_interpose():
assert Stream.range(5, 9).interpose(0).to_list() == [5, 0, 6, 0, 7, 0, 8]
assert Stream([]).interpose(0).to_list() == []
