lst = [1, 2, 3, 4]
print(lst. count (10))

s = "abc"
lst = [char.upper() for char in s]
print (lst)

nums = [1, 2, 3, 4, 5, 6]
evens = [n if n % 2 == 0 else "odd" for n in nums]
print (evens)

from itertools import product

a = [1, 2]
b = [3, 4]
result = list(product(a, b))
print(result)  # [(1, 3), (1, 4), (2, 3), (2, 4)]

from itertools import permutations

s = 'abc'
result = list(permutations(s))
print(result)  
# [('a', 'b', 'c'), ('a', 'c', 'b'), ('b', 'a', 'c'), 
#  ('b', 'c', 'a'), ('c', 'a', 'b'), ('c', 'b', 'a')]

from itertools import combinations

a = [1, 2, 3, 4]
result = list(combinations(a, 3))
print(result)  # [(1, 2, 3), (1, 2, 4), (1, 3, 4), (2, 3, 4)]

from itertools import chain

a = [1, 2, 3]
b = ['a', 'b', 'c']
result = list(chain(a, b))
print(result)  # [1, 2, 3, 'a', 'b', 'c']

from itertools import cycle

a = [1, 2, 3]
a1 = cycle(a)
for i in range(6):
    print(next(a1))  # 1, 2, 3, 1, 2, 3

from itertools import islice

a = range(1, 11)
slicea = islice(a, 2, 7)
print(list(slicea))  # [3, 4, 5, 6, 7]

from itertools import count

for i in count(3):
    if i > 10:
        break
    print(i)  # 3, 4, 5, 6, 7, 8, 9, 10

from itertools import product

k = 0
for i in product("ПЛАН", repeat=3):
    s = ''.join(i)
    if s.count('А') >= 1:
        k += 1
print(k)  # Ответ: 37

from itertools import permutations

k = 0
for i in permutations("РУСЛАН"):
    s = ''.join(i)
    if 'УА' not in s and 'АУ' not in s:
        k += 1
print(k)  # Ответ: 480