Terraria Mobile Save Encrypt/Decrypt

import os
import sys
import struct

from Crypto.Cipher import Blowfish  #pip install pycrypto

FILE_DIR = "files"
OUT_DIR = "output"

BLOCK_SIZE = 8

for single in [FILE_DIR, OUT_DIR]:
    if not os.path.isdir(single):
        os.mkdir(single)

player_key = "0d710d1d63ff36fe9bafd4c3874c64dd"
world_key = "9ae3efe6a4debdeb8290eabd5f832ad4"

def encrypt_player(dec_data, version = 24):
    bf = Blowfish.new(player_key, Blowfish.MODE_ECB)
    return struct.pack("<h", version) + bf.encrypt(dec_data)

def decrypt_player(enc_data):
    bf = Blowfish.new(player_key, Blowfish.MODE_ECB)
    #might do something with this
    save_version = struct.unpack("<h", enc_data[:2])
    return bf.decrypt(enc_data[:2])

def encrypt_world(dec_data, version = 24):
    bf = Blowfish.new(world_key, Blowfish.MODE_ECB)
    return struct.pack("<h", version) + bf.encrypt(dec_data)

def decrypt_world(enc_data):
    bf = Blowfish.new(world_key, Blowfish.MODE_ECB)
    #might do something with this
    save_version = struct.unpack("<h", enc_data[:2])
    return bf.decrypt(enc_data[2:])

argc = len(sys.argv)

if argc == 3:
    mode = sys.argv[1]
    filename = sys.argv[2]
    load_path = os.path.join(FILE_DIR, filename)
    if os.path.isfile(load_path):
        save_file = open(load_path, "rb").read()
        (base_name, ext) = os.path.basename(filename).split(".", 1)
        if ext == "player":
            if mode == "encrypt":
                encrypted = encrypt_player(save_file)
                save_path = os.path.join(OUT_DIR, "enc-" + base_name + "." + ext)
                open(save_path, "wb").write(encrypted)
            elif mode == "decrypt":
                decrypted = decrypt_player(save_file)
                save_path = os.path.join(OUT_DIR, "dec-" + base_name + "." + ext)
                open(save_path, "wb").write(decrypted)
            else:
                print "Invalid Mode"
        elif ext == "world":
            if mode == "encrypt":
                encrypted = encrypt_world(save_file)
                save_path = os.path.join(OUT_DIR, "enc-" + base_name + "." + ext)
                open(save_path, "wb").write(encrypted)
            elif mode == "decrypt":
                decrypted = decrypt_world(save_file)
                save_path = os.path.join(OUT_DIR, "dec-" + base_name + "." + ext)
                open(save_path, "wb").write(decrypted)
            else:
                print "Invalid Mode"
        else:
            print "Invalid File Type"
    else:
        print "File Doesn't Exist"
else:
    print "Usage: python terraria.py (encrypt/decrypt) (filename)"