def test_normal():
"""Test grouper."""
# grouper with multiple
data = iter('ABCDEF')
res = grouper(data, 2)
assert next(res) == ('A', 'B')
assert list(res) == [('C', 'D'), ('E', 'F')]
assert list(data) == []
# grouper with non-multiple
data = iter('ABCDE')
res = grouper(data, 2)
assert next(res) == ('A', 'B')
assert list(res) == [('C', 'D'), ('E', None)]
assert list(data) == []
# grouper with non-multiple but fillvalue used
data = iter('ABCDE')
res = grouper(data, 2, fillvalue='X')
assert next(res) == ('A', 'B')
assert list(res) == [('C', 'D'), ('E', 'X')]
assert list(data) == []
# grouper with empty
data = ()
res = grouper(data, 2)
assert list(res) == []
# grouper with 0 specified
data = iter('ABCDE')
res = grouper(data, 0)
assert list(res) == []
assert list(data) == ['A', 'B', 'C', 'D', 'E']
def test_normal_peek():
"""Test grouper with peeking at iterable."""
# grouper with multiple but peek makes it non-multiple
data = iter('ABCDEF')
res = grouper(data, 2)
assert next(res) == ('A', 'B')
assert next(data) == 'C'
assert list(res) == [('D', 'E'), ('F', None)]
assert list(data) == []
# grouper with non-multiple but peek makes it multiple
data = iter('ABCDE')
res = grouper(data, 2)
assert next(res) == ('A', 'B')
assert next(data) == 'C'
assert list(res) == [('D', 'E')]
assert list(data) == []
# grouper with multiple but peek makes it non-multiple but fillvalue used
data = iter('ABCDEF')
res = grouper(data, 2, fillvalue='X')
assert next(res) == ('A', 'B')
assert next(data) == 'C'
assert list(res) == [('D', 'E'), ('F', 'X')]
assert list(data) == []
def test_oddity():
"""Test oddities of grouper."""
# grouper with -1 specified
data = iter('ABCDE')
res = grouper(data, -1)
assert list(res) == []
assert list(data) == ['A', 'B', 'C', 'D', 'E']
# grouper of empty with -1 specified
data = ()
res = grouper(data, -1)
assert list(res) == []
