string == not working

This was working a few minutes ago but now I can't get it to work at all.

for i in range(0, len(find)):
    for j in range(0, len(X)):
        print(find[i], X[j])
        if find[i] == X[j]:
            longitude.append(float(lon[j]));
            latitude.append(float(lat[j]));

print(len(longitude))

LS5  LS6
LS5  LS7
LS5  LS6
LS5  LS7
LS6  LS6
...
0

for some reason its clearly equal but doesn't go through the if statement. any idea why this is happening?