Rc4 python implement

RC4crypt.py

def RC4crypt(data, key):
    '''
    http://en.wikipedia.org/wiki/RC4
    '''
    box_range = 256

    box = range(box_range)
    i = 0
    for j in range(box_range):
        i = (i + box[j] + ord(key[j % len(key)])) % box_range
        box[j], box[i] = box[i], box[j]

    i = j = 0
    out = []
    for c in data:
        i = (i + 1) % box_range
        j = (j + box[i]) % box_range
        box[i], box[j] = box[j], box[i]
        out.append(chr(ord(c) ^ box[(box[i] + box[j]) % 256]))

    return ''.join(out)