eight.py

import unittest
from functools import reduce
from itertools import islice

# Find the thirteen adjacent digits in the 1000-digit digits that have the greatest max_product. What is the value of this max_product?
number = 7316717653133062491922511967442657474235534919493496983520312774506326239578318016984801869478851843858615607891129494954595017379583319528532088055111254069874715852386305071569329096329522744304355766896648950445244523161731856403098711121722383113622298934233803081353362766142828064444866452387493035890729629049156044077239071381051585930796086670172427121883998797908792274921901699720888093776657273330010533678812202354218097512545405947522435258490771167055601360483958644670632441572215539753697817977846174064955149290862569321978468622482839722413756570560574902614079729686524145351004748216637048440319989000889524345065854122758866688116427171479924442928230863465674813919123162824586178664583591245665294765456828489128831426076900422421902267105562632111110937054421750694165896040807198403850962455444362981230987879927244284909188845801561660979191338754992005240636899125607176060588611646710940507754100225698315520005593572972571636269561882670428252483600823257530420752963450


def calculate():
    digits = str(number)
    return max(
        reduce(lambda x, y: int(x) * int(y), islice(digits, x, x + 13), 1)
        for x in range(len(digits) - 12)
    )


# def calculate():
#     input_length = len(str(digits))
#     window = 13
#     current_position = 0
#     max_product = 0
#     product = 0

#     for _ in islice(str(digits),0,)

#     while current_position <= int(input_length - window):
#         product = reduce(lambda x, y: int(x) * int(y),
#             str(digits)[current_position : current_position + window],
#         )

#         if max_product < product:
#             max_product = product
#         current_position = current_position + 1

#     return max_product


class Test(unittest.TestCase):
    def test_find_nine(self):
        self.assertEqual(calculate(), 23514624000)


if __name__ == "__main__":
    unittest.main()