maximum_subarray.py

from collections.abc import Sequence


def max_subarray_sum(nums: Sequence[int]) -> int:
 """Return the maximum possible sum amongst all non - empty subarrays.

 Raises:
 ValueError: when nums is empty.

 >>> max_subarray_sum([1,2,3,4,-2])
 10
 >>> max_subarray_sum([-2,1,-3,4,-1,2,1,-5,4])
 6
 """
 if not nums:
 raise ValueError("Input sequence should not be empty")

 curr_max = ans = nums[0]
 nums_len = len(nums)

 for i in range(1, nums_len):
 num = nums[i]
 curr_max = max(curr_max + num, num)
 ans = max(curr_max, ans)

 return ans


if __name__ == "__main__":
 n = int(input("Enter number of elements : ").strip())
 array = list(map(int, input("\nEnter the numbers : ").strip().split()))[:n]
 print(max_subarray_sum(array))