from itertools import chain
test = chain('AB', 'CDE', 'F')
for el in test:
  print(el)

"""
A
B
C
D
E
F
"""

from itertools import chain

for i in chain([1,2,3], ['a', 'b', 'c']):
    print (i)

"""
1
2
3
a
b
c
"""

from itertools import starmap

values = [[0,5], [1,6], [2,7], [3,8]]

for i in starmap(lambda x, y:(x, y, x+y), values):
    print ('%d * %d = %d' % i)

"""
0 * 5 = 5
1 * 6 = 7
2 * 7 = 9
3 * 8 = 11

"""

from itertools import combinations
test = combinations([1, 2, 3, 4], 2)
for el in test:
    print(el)

"""
(1, 2)
(1, 3)
(1, 4)
(2, 3)
(2, 4)
(3, 4)

"""

from itertools import compress
letters = 'ABCDEFG'
bools = [True, False, True, True,False]
ret = list(compress(letters, bools))
print(ret)
"""
['A', 'C', 'D']
"""

from itertools import filterfalse
def greater_than_five(x):
    return x > 5

ret = list(filterfalse(greater_than_five, [0,6, 7, 8, 9, 1, 2, 3, 10,2]))
print(ret)

"""
[0, 1, 2, 3, 2]
"""

from itertools import islice
iterator = islice('123456', 4)

print(next(iterator))
print(next(iterator))
print(next(iterator))
print(next(iterator))

"""

1
2
3
4

"""

from itertools import cycle
polys = ['13579', '02468', '56789', '01234']
iterator = cycle(polys)
print(next(iterator))
print(next(iterator))
print(next(iterator))
print(next(iterator))
print(next(iterator))
print(next(iterator))

"""
13579
02468
56789
01234
13579
02468
"""

#repeat(物件[, 次數])
from itertools import repeat
iterator = repeat("123", 5)

print(next(iterator))
print(next(iterator))
print(next(iterator))
print(next(iterator))
print(next(iterator))
print(next(iterator))

from itertools import starmap
def add(a, b):
    return a+b

for item in starmap(add, [[2,3], (4,5),(7,8)]):
    print(item)

"""
5
9
15
"""