Random walk's weird outcome in python 3?

I just start learning python and have a problem to print a new location of random walk in 3 dimensions. There is no error popping up, but it's obvious that the output (x, y, z) being printed is unreasonable! When simulating random walk step by step, I assume only one value in the (x, y, z) should be changed in each time. But it seems not in the output. I'm trying to debug it but still confused about identifying what the real problem is.

The output's head lines:

(0,-1,1)
(-1,0,1)
(-2,0,1)
(-2,1,2)
(-2,2,2)
(-2,2,3)
(-1,2,3)
(0,1,3)

My motivation:

The purpose of this code is to simulate N steps of a random walk in 3 dimensions. At each step, a random direction is chosen (north, south, east, west, up, down) and a step of size 1 is taken in that direction. The new location is then printed. The starting location is the origin (0, 0, 0).

My code:

import pdb
import random  # this helps us generate random numbers
N = 30  # number of steps
n = random.random()  # generate a random number

x = 0
y = 0
z = 0
count = 0 
while count <= N:
  if n < 1/6:
      x = x + 1           # move east
      n = random.random() # generate a new random number
  if n >= 1/6 and n < 2/6:
      y = y + 1           # move north
      n = random.random() # generate a new random number
  if n >= 2/6 and n < 3/6:
      z = z + 1           # move up
      n = random.random() # generate a new random number
  if n >= 3/6 and n < 4/6:
      x = x - 1           # move west
      n = random.random() # generate a new random number
  if n >= 4/6 and n < 5/6:
      y = y - 1           # move south
      n = random.random() # generate a new random number
  if n >= 5/6:
      z = z - 1           # move down
      n = random.random() # generate a new random number

  print("(%d,%d,%d)" % (x,y,z)) 
  count = count + 1
print("squared distance = %d" % (x*x + y*y + z*z))

Environment:

Python 3.5 in Jupyter Notebook, Windows 10, Dell XPS 13