>>>Available operations:
      1. Addition
      2. Subtraction
      3. Multiplication
      4. Division
 
      Choose an operation: 1
      Enter first number: 2
      Enter second number: 3
      2 + 3 = 5
 
Available operations:
....
....

# exploring Tkinter's canvas drawing surface
# draw lines and ovals to form a stick man
# info at http://effbot.org/tkinterbook/canvas.htm
 
try:
    # Python2
    import Tkinter as tk
except ImportError:
    # Python3
    import tkinter as tk
 
def body(w, h):
    """draw the oval for the body"""
    # an oval is drawn within a given rectangle
    # (x1, y1, x2, y2) upper left and lower right corner coordinates
    # of the rectangle the ellipse is bound by
    # calculate coordinates relative to width w and height h
    rect = (w//2-80, h//2-150, w//2+80, h//2+80)
    canvas.create_oval(rect, fill='red')    
 
def head(w, h):
    """draw the oval/circle for the head"""
    # if the bounding rectangle is a square a circle is drawn
    rect = (w//2-40, h//2-230, w//2+40, h//2-150)
    canvas.create_oval(rect, fill='red')     
 
def arms(w, h):
    """draw lines for right and left arm"""
    # draw line from coordinate points x1, y1 to x, y2
    # left arm
    canvas.create_line(w//2-66, h//2-100, w//2-166, h//2-50)
    # right arm
    canvas.create_line(w//2+66, h//2-100, w//2+166, h//2-50)
 
def legs(w, h):
    """draw lines for right and left legs"""
    # draw line from coordinate points x1, y1 to x, y2
    # left leg
    canvas.create_line(w//2-55, h//2+50, w//2-76, h//2+190)
    # right leg
    canvas.create_line(w//2+55, h//2+50, w//2+76, h//2+190)
 
 
# create the main window
root = tk.Tk()
root.title("Fred Stickman")
 
# create the drawing canvas
w = 400
h = 500
canvas = tk.Canvas(root, width=w, height=h, bg='white')
canvas.pack()
 
body(w, h)
head(w, h)
arms(w, h)
legs(w, h)
 
# start the GUI event loop
root.mainloop()

# using Python module os to create random values
 
import os
 
n = 35
# returns a string of n random bytes
random_bytes = os.urandom(n)
# some bytes may not be printable
# so create a string of all the printable bytes
random_str = ""
for byt in random_bytes:
    # select ascii printable bytes/characters
    if 32 < ord(byt) < 127:
        random_str += byt
print(random_str)
 
for k in range(10):
    # random integer from 0 to 255
    random_integer = ord(os.urandom(1))
    print(random_integer)