generates random Visa card number passing Luhn check (in Pythonista)

Visa

#coding: utf-8
# generates random Visa card number passing Luhn check
import clipboard
import numpy as np
from decimal import Decimal

def split_cc(ccnum):
	cclist = list(str(ccnum))
	cclist.insert(4, ' ')
	cclist.insert(9, ' ')
	cclist.insert(14, ' ')
	return ''.join(cclist)

def luhn(ccnum): # works with leading zeros
	# checks if ccnum satisfies Luhn algoritm [doesn't matter how long ccnum is]
	ccdec = Decimal(ccnum).as_tuple().digits # converte ccnum to tuple of digits
	# followoing if statement is used only for partial numbers with leading zeros
	if len(ccdec) > 4 and len(ccdec) <> 16:
		return False
	if len(ccdec) == 3:
		ccdec = tuple([0]+list(ccdec))
	elif len(ccdec) == 2:
		ccdec = tuple([0, 0]+list(ccdec))
	elif len(ccdec) == 1:
		ccdec = tuple([0, 0, 0]+list(ccdec))
	elif len(ccdec) == 0:
		ccdec = tuple([0, 0, 0, 0])
	# now use Luhn algoritm
	cint = 0
	i = 0
	for c in ccdec:
		if i%2 == 0:
			t = c*2
			if t > 9:       #if two digit number
				t = t%10 + 1    #same as above but simpler; max = 9*2 = 18
		else:
			t = c
		cint += t * 10**i
		i += 1
	k =  sum(Decimal(cint).as_tuple().digits) # sum decimal digits
	return k%10 == 0

i = 0
cc = "" #credit card number string
while i < 4: #generate 4 groups of 4 digits
# this 4x4 approach is quicker
# if each group satisfies the Luhn condition then the whole number (usually) will...
# anyway we will run luhn() check on whole 16 digits at the end
	q = 1111    # start loop with False condition
	while luhn(q) <> True: #loop until you find 4 digits that satisfy Luhn
		if i > 0:
			q = np.random.randint(9999)
			c = str(q)
			while len(c) < 4: #if less then 4 digits add leading zeros to string representation
				c = str(0) + c
			q = int(c)
		else:                               # leading 4 digits
			q = np.random.randint(999)
			c = str(q)
			while len(c) < 3: #if less then 3 digits add leading zeros to string representation
				c = str(0) + c
			c = str(4) + c      #and start visa number with 4
			q = int(c)

	cc = cc + c
	i += 1 # done. go and find next group

print "You new Visa number is: \n" + split_cc(long(cc))
clipboard.set(cc)
print "Credit card number copied to Clipboard"
print cc[:6] + 'X' * 6 + cc[-4:]
print "Visa check result is: " + str( luhn(long(cc)) ) #check if the the whole number is valid