Euler #81

raw = list(open('/p081_matrix.txt'))
visited, shortTrack, lengths, shortSaved = [], [4445] + [10**10]*(80**2-1), [], [4445] + [10**10]*(80**2-1)
for a in raw:
    a.rstrip('\n')
    tempString = ""
    for b in a:
        if b == ",":
            lengths.append(int(tempString))
            tempString = ""
            continue
        tempString += b
    lengths.append(int(tempString))
while len(visited) != 6400:
    start = shortTrack.index(min(shortTrack))
    try:
        if start % 80 != 79 and start + 1 not in visited:
            if shortSaved[start] + lengths[start + 1] < shortSaved[start + 1]:
                shortSaved[start + 1] = shortSaved[start] + lengths[start + 1]
                shortTrack[start + 1] = shortSaved[start] + lengths[start + 1]
    except IndexError:
        pass
    try:
        if start <= 80**2 - 81 and start + 80 not in visited:
            if shortSaved[start] + lengths[start + 80] < shortSaved[start + 80]:
                shortSaved[start + 80] = shortSaved[start] + lengths[start + 80]
                shortTrack[start + 80] = shortSaved[start] + lengths[start + 80]
    except IndexError:
        pass
    visited.append(start)
    shortTrack[start] = 10**10
print(shortSaved[80**2-1])