# Feel free to do anything with this code.
# Nicolas Fleury (nid_oizo@yahoo.com_remove_the_)

import sys

def splitall(path):
    if sys.platform == 'win32':
        all = path.replace('/', '\\').split('\\')
        if len(all[0]) == 2 and all[0][1] == ':':
            all[0] = all[0] + '\\'
        elif all[0] == '':  # path was beginning with \ or /
            all[0] = '/'
        if all[-1] == '': all = all[:-1]
        return all
    else:
        all = path.split('/')
        if all[0] == '':  # path was beginning with \ or /
            all[0] = '/'
        if all[-1] == '': all = all[:-1]
        return all

def abstorel(path, relToPath):
    "Make an absolute path relative to another path."
    if not os.path.isabs(path):
        raise Exception('Path "' + path + '" should be absolute')
    if not os.path.isabs(relToPath):
        raise Exception('Path "' + relToPath + '" should be absolute')
    all = splitall(path)
    if sys.platform == 'win32':
        if (os.path.splitdrive(path)[0] and os.path.splitdrive(relToPath)[0] and
            os.path.splitdrive(path)[0] != os.path.splitdrive(relToPath)[0]):
            return path  # different drives; keep absolute
    path = splitall(path)[1:]
    relToPath = splitall(relToPath)[1:]
    samePathCount = 0
    for i in range(max(len(path), len(relToPath))):
        if path[i] != relToPath[i]:
            break
        samePathCount += 1
    newPath = ['..'] * (len(relToPath) - samePathCount)
    newPath += path[samePathCount:]
    return "\\".join(newPath)