Output conditions

Hello

I'm just starting to learn python. I am writing the code below to output a random number with length s including 0,1,2,3.

import numpy as np

n_one =int(input('Insert the amount of 1: '))
n_two =int(input('Insert the amount of 2: '))
n_three = int(input('Insert the amount of 3: '))
l = n_one+n_two+n_three
n_zero = l+1
s = (2*(n_zero))-1


data = [0]*n_zero + [1]*n_one + [2]*n_two + [3]*n_three
print ("Data string length is %d"  % len(data))

while data[0] == 0 and data[s-1]!=0:
         np.random.shuffle(data)
datastring = ''.join(map(str, data))
datastring = str(int(datastring))
files = open('decode.txt', 'w')
files.write(datastring)
files.write('\n')
files.close()
print("Data string is : %s " % datastring)

The problem is the output. I want the output to start with a non-zero number and end with 0. For now, using while minutes, sometimes it doesn't work very well. If you have any suggestions, thank you.