Python 3 code
##########################################################
# Sequential ordered steps of a 2D Julia set generation
# (c=0.7454294)
# (graphics module)
##########################################################

# specify the absolute path of mod graphics folder (depends on user's choice)
import sys
sys.path.append("/Users/strumia/Library/Python/3.6/site-packages/graphics/")

from graphics import*   # import graphics module

Radius = 10   # set escape rate threshold
Cx = 0.7454294   # set c  parameter real part value
Cy = 0.0   # set c  parameter imaginary part value
Side = 1.7   # set square area side
M = 300    # set side number of elementary squares
N = 1   # set color map scale factor
Num = 256*N   # set number of cycles
sT=3  #  set step jump

win = GraphWin("Julia set", 5*M/3,5*M/3)  # set window title
win.setBackground("white")     # set background color

def rectCol(p,q,w):   # define elementary cell
    Rect = Rectangle(Point(int(p-sT/2),int(q-sT/2)),
    Point(int(p+sT/2),int(q+sT/2)))
    Rect.draw(win).setFill(color_rgb(int(w),int(128-w/2),
    int(128+w/2)))

for p in range(1,M,sT):   # column scanning cycle
  Incy = - Side + 2*Side/M*p   # define column scanning function
  for q in range(1,M,sT):   # raw scanning cycle
    Incx = - Side + 2*Side/M*q   # define raw scanning function
    x = Incx   # set starting increment of x co-ordinate
    y = Incy   # set starting increment of y co-ordinate
    w = 0   # set starting escape modulus value
    for n in range(1,Num):  # recursion cycle
      xx = x*x - y*y - Cx
      yy = 2*x*y - Cy
      x = xx
      y = yy
      if x*x + y*y > Radius:   # escape rate condition
        w = n/N   # escape modulus normalization
        rectCol(int(M/3+q),int(M/3+p),int(w))   # plot elementary cell
        break  # interrupt cycle

win.getMouse()   # wait for mouse click
win.close()   # close window