Maximum-Sum Path in a Number Triangle

tri = []

def loadTriangle():
    while len(tri) > 0:
        del tri[0]

    try:
        load = open(input('Filename? -={ '), 'r')
    except FileNotFoundError:
        print('Error: File not found...')
        return

    conts = load.read()
    for line in conts.split('\n'):
        temp = []

        for bit in line.split(' '):
            temp.append(int(bit))

        tri.append(temp)

    for line in tri:
        for bit in line:
            print(bit, end = ' ')
        print()

def maxPath():
    line = len(tri) - 2
    below = tri[line + 1]
    Idxs = []
    bIdxs = []
    currSums = []

    while line >= 0:
        current = tri[line]

        for i in range(len(current)):
            choices = below[i:i+2]

            bIdxs.append(i + choices.index(max(choices)))

            currSums.append(current[i] + max(choices))

        line -= 1
        below = currSums
        Idxs.insert(0, bIdxs)
        bIdxs = []
        currSums = []

    line = 0
    bigSum = 0
    maxIdx = 0
    while line < len(tri):
        print(tri[line][maxIdx], end = '')
        bigSum += tri[line][maxIdx]

        if line + 1 < len(tri):
            maxIdx = Idxs[line][maxIdx]
            print(' + ', end = '')

        line += 1

    print(' =', bigSum)

    return below[0]

loadTriangle()
maxPath()