Image steganography using python

from PIL import Image
	def genData(data):
	# list of binary codes
	# of given data
	newd = []
	for i in data:
	newd.append(format(ord(i), '08b'))
	return newd
	# Pixels are modified according to the
	# 8-bit binary data and finally returned
	def modPix(pix, data):
	datalist = genData(data)
	lendata = len(datalist)
	imdata = iter(pix)
	for i in range(lendata):
	# Extracting 3 pixels at a time
	pix = [value for value in imdata.next()[:3] +
	imdata.next()[:3] +
	imdata.next()[:3]]
	# Pixel value should be made
	# odd for 1 and even for 0
	for j in range(0, 8):
	if (datalist[i][j]=='0') and (pix[j]% 2 != 0):
	if (pix[j]% 2 != 0):
	pix[j] -= 1
	elif (datalist[i][j] == '1') and (pix[j] % 2 == 0):
	pix[j] -= 1
	# Eigh^th pixel of every set tells
	# whether to stop ot read further.
	# 0 means keep reading; 1 means the
	# message is over.
	if (i == lendata - 1):
	if (pix[-1] % 2 == 0):
	pix[-1] -= 1
	else:
	if (pix[-1] % 2 != 0):
	pix[-1] -= 1
	pix = tuple(pix)
	yield pix[0:3]
	yield pix[3:6]
	yield pix[6:9]
	def encode_enc(newimg, data):
	w = newimg.size[0]
	(x, y) = (0, 0)
	for pixel in modPix(newimg.getdata(), data):
	# Putting modified pixels in the new image
	newimg.putpixel((x, y), pixel)
	if (x == w - 1):
	x = 0
	y += 1
	else:
	x += 1
	# Encode data into image
	def encode():
	print "Encode"
	img = raw_input("Enter image name(with extension): ")
	image = Image.open(img, 'r')
	image.show()
	data = raw_input("Enter data to be encoded : ")
	if (len(data) == 0):
	raise ValueError('Data is empty')
	newimg = image.copy()
	encode_enc(newimg, data)
	new_img_name = raw_input("Enter the name of new image(with extension): ")
	newimg.save(new_img_name, str(new_img_name.split(".")[1].lower()))
	# Decode the data in the image
	def decode():
	print "Decode"
	img = raw_input("Enter image name(with extension) :")
	image = Image.open(img, 'r')
	image.show()
	data = ''
	imgdata = iter(image.getdata())
	while (True):
	pixels = [value for value in imgdata.next()[:3] +
	imgdata.next()[:3] +
	imgdata.next()[:3]]
	# string of binary data
	binstr = ''
	for i in pixels[:8]:
	if (i % 2 == 0):
	binstr += '0'
	else:
	binstr += '1'
	data += chr(int(binstr, 2))
	if (pixels[-1] % 2 != 0):
	return data
	# Main Function
	def main():
	#declaring key
	pkey = 123
	a = int(raw_input(":: Image Steganography ::\n"
	"1.Encrypt\n2.Decrypt\n"))
	if (a == 1):
	print("Encryption")
	encode()
	print("Data has sucessfully Encrpyted")
	elif (a == 2):
	print("Decryption")
	Pkey = int(raw_input("Enter the key to be decrypted : "))
	if(pkey == Pkey):
	print("--Decoded word-- " + decode())
	else :
	raise Exception("Enter correct key")
	else:
	raise Exception("Enter correct input")
	# Driver Code
	if __name__ == '__main__' :
	# Calling main function
	main() Support: Delta For more info : https://github.com/SharathHebbar/Image-steganography/blob/master/image.py