this is simple json validate and encrypted file generating python script

json_encrypt.py

__author__ = 'huhushow'
import json, sys, getopt, base64, hashlib
from Crypto import Random
from Crypto.Cipher import AES

BS = 16
pad = lambda s: s + (BS - len(s) % BS) * chr(BS - len(s) % BS).encode()
unpad = lambda s: s[:-ord(s[len(s)-1:])]

def iv():
	"""
	The initialization vector to use for encryption or decryption.
	It is ignored for MODE_ECB and MODE_CTR.
	"""
	return chr(0) * 16
	
class AESCipher(object):
	"""
	https://github.com/dlitz/pycrypto
	"""

	def __init__(self):
		self.key = 'abcdefghijklmnopqrstuvwxyz1234567890'
		#self.key = hashlib.sha256(key.encode()).digest()

	def encrypt(self, message):
		"""
		It is assumed that you use Python 3.0+
		, so plaintext's type must be str type(== unicode).
		"""
		message = message.encode()
		raw = pad(message)
		cipher = AES.new(self.key, AES.MODE_CBC, iv())
		enc = cipher.encrypt(raw)
		return base64.b64encode(enc).decode('utf-8')

	def decrypt(self, enc):
		enc = base64.b64decode(enc)
		cipher = AES.new(self.key, AES.MODE_CBC, iv())
		dec = cipher.decrypt(enc)
		return unpad(dec).decode('utf-8')

def main():
	try:
		argv_short = "hi:o:"
		argv_long = ["help","input_file=","output_file="]
		opts, args = getopt.getopt(sys.argv[1:], argv_short, argv_long)
	except getopt.GetoptError as err:
		print(err)
		usage()
		sys.exit(2)
	infile = None
	indata = None
	outfile_name = None
	outfile = None
	verbose = False
	for o, a in opts:
		if o == "-v":
			verbose = True
		elif o in ("-h", "--help"):
			usage()
			sys.exit()
		elif o in ("-i", "--input_file"):
			infile = open(a, 'r')
		elif o in ("-o", "--output_file"):
			outfile_name = a
		else:
			assert False, "unhandled option"
		
	indata = infile.read()
	infile.close()
	try:
		json.loads(indata)
	except ValueError as err:
		print(err)
		sys.exit(2)
	
	encypted = AESCipher().encrypt(indata)
	outfile = open(outfile_name, 'w')
	outfile.write(encypted)
	outfile.close()
def usage():
	usage = """
	check input files json validate 
	and output encrypted file
	-h --help		Print this
	-i --input_file		input plain file name
	-o --output_file	output encrypted file name
	"""
	print(usage)

if __name__ == "__main__":
	main()