Buggy python submission (verdict: Time Limit Exceeded):
import sys
sys.setrecursionlimit(10**7)
def input(): return sys.stdin.readline().rstrip()


def main():
    _ = int(input())
    hoge = tuple(map(int, input().split()))
    sumn = 0
    mod = 10 ** 9 + 7

    for h in range(len(hoge)):
        if h+1 <= len(hoge):
            for hh in range(h+1, len(hoge)):
                sumn += hoge[h] * hoge[hh]
                sumn %= mod
    print(sumn)


if __name__ == '__main__':
    main()

Fixed submission:
import sys
sys.setrecursionlimit(10**7)
def input(): return sys.stdin.readline().rstrip()


def main():
    _ = int(input())
    nums = tuple(map(int, input().split()))
    mod = 10 ** 9 + 7

    num_sum = sum(nums)
    part_sum = sum(map(lambda x: x**2, nums)) # naname

    print((num_sum**2 - part_sum) // 2 % mod)


if __name__ == '__main__':
    main()

Buggy python submission (verdict: Time Limit Exceeded):
import itertools
import sys
sys.setrecursionlimit(10**7)
def input(): return sys.stdin.readline().rstrip()


def main():
    _ = int(input())
    hoge = tuple(map(int, input().split()))
    sumn = 0
    mod = 10 ** 9 + 7
    for pair in itertools.combinations(hoge, 2):
        sumn += (pair[0] * pair[1])
        sumn %= mod
    print(sumn)


if __name__ == '__main__':
    main()


Fixed submission:
import sys
sys.setrecursionlimit(10**7)
def input(): return sys.stdin.readline().rstrip()


def main():
    _ = int(input())
    nums = tuple(map(int, input().split()))
    mod = 10 ** 9 + 7

    num_sum = sum(nums)
    part_sum = sum(map(lambda x: x**2, nums)) # naname

    print((num_sum**2 - part_sum) // 2 % mod)


if __name__ == '__main__':
    main()

Buggy python submission (verdict: Time Limit Exceeded):
import itertools
import sys
sys.setrecursionlimit(10**7)
def input(): return sys.stdin.readline().rstrip()


def main():
    _ = int(input())
    hoge = tuple(map(int, input().split()))
    sumn = 0
    mod = 10 ** 9 + 7
    for pair in itertools.combinations(hoge, 2):
        sumn += (pair[0] * pair[1])
        sumn %= mod
    print(sumn)


if __name__ == '__main__':
    main()

Fixed submission:
import sys
sys.setrecursionlimit(10**7)
def input(): return sys.stdin.readline().rstrip()


def main():
    _ = int(input())
    nums = tuple(map(int, input().split()))
    mod = 10 ** 9 + 7

    num_sum = sum(nums)
    part_sum = sum(map(lambda x: x**2, nums)) # naname

    print((num_sum**2 - part_sum) // 2 % mod)


if __name__ == '__main__':
    main()

Buggy python submission (verdict: Time Limit Exceeded):
import itertools
import sys
sys.setrecursionlimit(10**7)
def input(): return sys.stdin.readline().rstrip()


def main():
    _ = int(input())
    hoge = tuple(map(int, input().split()))
    sumn = 0
    mod = 10 ** 9 + 7
    for pair in list(itertools.combinations(hoge, 2)):
        sumn += (pair[0] * pair[1])
        sumn %= mod
    print(sumn)


if __name__ == '__main__':
    main()

Fixed submission:
import sys
sys.setrecursionlimit(10**7)
def input(): return sys.stdin.readline().rstrip()


def main():
    _ = int(input())
    nums = tuple(map(int, input().split()))
    mod = 10 ** 9 + 7

    num_sum = sum(nums)
    part_sum = sum(map(lambda x: x**2, nums)) # naname

    print((num_sum**2 - part_sum) // 2 % mod)


if __name__ == '__main__':
    main()