--- /dev/null
+This directory contains a collection of demonstration scripts for
+various aspects of Python programming.
+
+beer.py Well-known programming example: Bottles of beer.
+eiffel.py Python advanced magic: A metaclass for Eiffel post/preconditions.
+hanoi.py Well-known programming example: Towers of Hanoi.
+life.py Curses programming: Simple game-of-life.
+markov.py Algorithms: Markov chain simulation.
+mcast.py Network programming: Send and receive UDP multicast packets.
+queens.py Well-known programming example: N-Queens problem.
+redemo.py Regular Expressions: GUI script to test regexes.
+rpython.py Network programming: Small client for remote code execution.
+rpythond.py Network programming: Small server for remote code execution.
+sortvisu.py GUI programming: Visualization of different sort algorithms.
+ss1.py GUI/Application programming: A simple spreadsheet application.
+vector.py Python basics: A vector class with demonstrating special methods.
\ No newline at end of file
-#! /usr/bin/env python3
+#!/usr/bin/env python3
-# By GvR, demystified after a version by Fredrik Lundh.
+"""
+A Python version of the classic "bottles of beer on the wall" programming
+example.
+
+By Guido van Rossum, demystified after a version by Fredrik Lundh.
+"""
import sys
-"""Support Eiffel-style preconditions and postconditions."""
+#!/usr/bin/env python3
+"""
+Support Eiffel-style preconditions and postconditions for functions.
+
+An example for Python metaclasses.
+"""
+
+import unittest
from types import FunctionType as function
class EiffelBaseMetaClass(type):
def __new__(meta, name, bases, dict):
meta.convert_methods(dict)
- return super(EiffelBaseMetaClass, meta).__new__(meta, name, bases,
- dict)
+ return super(EiffelBaseMetaClass, meta).__new__(
+ meta, name, bases, dict)
@classmethod
def convert_methods(cls, dict):
if pre or post:
dict[k] = cls.make_eiffel_method(dict[m], pre, post)
+
class EiffelMetaClass1(EiffelBaseMetaClass):
# an implementation of the "eiffel" meta class that uses nested functions
def method(self, *args, **kwargs):
if pre:
pre(self, *args, **kwargs)
- x = func(self, *args, **kwargs)
+ rv = func(self, *args, **kwargs)
if post:
- post(self, x, *args, **kwargs)
- return x
+ post(self, rv, *args, **kwargs)
+ return rv
if func.__doc__:
method.__doc__ = func.__doc__
return method
+
class EiffelMethodWrapper:
def __init__(self, inst, descr):
def __call__(self, *args, **kwargs):
return self._descr.callmethod(self._inst, args, kwargs)
-class EiffelDescriptor(object):
+
+class EiffelDescriptor:
def __init__(self, func, pre, post):
self._func = func
self._post(inst, x, *args, **kwargs)
return x
+
class EiffelMetaClass2(EiffelBaseMetaClass):
# an implementation of the "eiffel" meta class that uses descriptors
make_eiffel_method = EiffelDescriptor
-def _test(metaclass):
- class Eiffel(metaclass=metaclass):
- pass
-
- class Test(Eiffel):
-
- def m(self, arg):
- """Make it a little larger"""
- return arg + 1
-
- def m2(self, arg):
- """Make it a little larger"""
- return arg + 1
-
- def m2_pre(self, arg):
- assert arg > 0
-
- def m2_post(self, result, arg):
- assert result > arg
-
- class Sub(Test):
- def m2(self, arg):
- return arg**2
- def m2_post(self, Result, arg):
- super(Sub, self).m2_post(Result, arg)
- assert Result < 100
-
- t = Test()
- t.m(1)
- t.m2(1)
- try:
- t.m2(0)
- except AssertionError:
- pass
- else:
- assert False
-
- s = Sub()
- try:
- s.m2(1)
- except AssertionError:
- pass # result == arg
- else:
- assert False
- try:
- s.m2(10)
- except AssertionError:
- pass # result == 100
- else:
- assert False
- s.m2(5)
+
+class Tests(unittest.TestCase):
+
+ def testEiffelMetaClass1(self):
+ self._test(EiffelMetaClass1)
+
+ def testEiffelMetaClass2(self):
+ self._test(EiffelMetaClass2)
+
+ def _test(self, metaclass):
+ class Eiffel(metaclass=metaclass):
+ pass
+
+ class Test(Eiffel):
+ def m(self, arg):
+ """Make it a little larger"""
+ return arg + 1
+
+ def m2(self, arg):
+ """Make it a little larger"""
+ return arg + 1
+
+ def m2_pre(self, arg):
+ assert arg > 0
+
+ def m2_post(self, result, arg):
+ assert result > arg
+
+ class Sub(Test):
+ def m2(self, arg):
+ return arg**2
+
+ def m2_post(self, Result, arg):
+ super(Sub, self).m2_post(Result, arg)
+ assert Result < 100
+
+ t = Test()
+ self.assertEqual(t.m(1), 2)
+ self.assertEqual(t.m2(1), 2)
+ self.assertRaises(AssertionError, t.m2, 0)
+
+ s = Sub()
+ self.assertRaises(AssertionError, s.m2, 1)
+ self.assertRaises(AssertionError, s.m2, 10)
+ self.assertEqual(s.m2(5), 25)
+
if __name__ == "__main__":
- _test(EiffelMetaClass1)
- _test(EiffelMetaClass2)
+ unittest.main()
-# Animated Towers of Hanoi using Tk with optional bitmap file in
-# background.
-#
-# Usage: tkhanoi [n [bitmapfile]]
-#
-# n is the number of pieces to animate; default is 4, maximum 15.
-#
-# The bitmap file can be any X11 bitmap file (look in
-# /usr/include/X11/bitmaps for samples); it is displayed as the
-# background of the animation. Default is no bitmap.
+#!/usr/bin/env python3
-# This uses Steen Lumholt's Tk interface
-from tkinter import *
+"""
+Animated Towers of Hanoi using Tk with optional bitmap file in background.
+Usage: hanoi.py [n [bitmapfile]]
+
+n is the number of pieces to animate; default is 4, maximum 15.
+
+The bitmap file can be any X11 bitmap file (look in /usr/include/X11/bitmaps for
+samples); it is displayed as the background of the animation. Default is no
+bitmap.
+"""
+
+from tkinter import Tk, Canvas
# Basic Towers-of-Hanoi algorithm: move n pieces from a to b, using c
# as temporary. For each move, call report()
self.pegstate[b].append(i)
-# Main program
def main():
import sys
#!/usr/bin/env python3
-# life.py -- A curses-based version of Conway's Game of Life.
-# Contributed by AMK
-# Mouse support and color by Dafydd Crosby
-#
-# An empty board will be displayed, and the following commands are available:
-# E : Erase the board
-# R : Fill the board randomly
-# S : Step for a single generation
-# C : Update continuously until a key is struck
-# Q : Quit
-# Cursor keys : Move the cursor around the board
-# Space or Enter : Toggle the contents of the cursor's position
-#
-# TODO :
-# Make board updates faster
-#
-
-import random, string, traceback
+
+"""
+A curses-based version of Conway's Game of Life.
+
+An empty board will be displayed, and the following commands are available:
+ E : Erase the board
+ R : Fill the board randomly
+ S : Step for a single generation
+ C : Update continuously until a key is struck
+ Q : Quit
+ Cursor keys : Move the cursor around the board
+ Space or Enter : Toggle the contents of the cursor's position
+
+Contributed by Andrew Kuchling, Mouse support and color by Dafydd Crosby.
+"""
+
import curses
+import random
+
class LifeBoard:
"""Encapsulates a Life board
next generation. Then display the state
of the board and refresh the screen.
erase() -- clear the entire board
- makeRandom() -- fill the board randomly
+ make_random() -- fill the board randomly
set(y,x) -- set the given cell to Live; doesn't refresh the screen
toggle(y,x) -- change the given cell from live to dead, or vice
versa, and refresh the screen display
# Draw a border around the board
border_line = '+'+(self.X*'-')+'+'
self.scr.addstr(0, 0, border_line)
- self.scr.addstr(self.Y+1,0, border_line)
+ self.scr.addstr(self.Y+1, 0, border_line)
for y in range(0, self.Y):
self.scr.addstr(1+y, 0, '|')
self.scr.addstr(1+y, self.X+1, '|')
def set(self, y, x):
"""Set a cell to the live state"""
if x<0 or self.X<=x or y<0 or self.Y<=y:
- raise ValueError("Coordinates out of range %i,%i"% (y,x))
+ raise ValueError("Coordinates out of range %i,%i"% (y, x))
self.state[x,y] = 1
def toggle(self, y, x):
"""Toggle a cell's state between live and dead"""
- if x<0 or self.X<=x or y<0 or self.Y<=y:
- raise ValueError("Coordinates out of range %i,%i"% (y,x))
- if (x,y) in self.state:
- del self.state[x,y]
+ if x < 0 or self.X <= x or y < 0 or self.Y <= y:
+ raise ValueError("Coordinates out of range %i,%i"% (y, x))
+ if (x, y) in self.state:
+ del self.state[x, y]
self.scr.addch(y+1, x+1, ' ')
else:
- self.state[x,y] = 1
+ self.state[x, y] = 1
if curses.has_colors():
- #Let's pick a random color!
- self.scr.attrset(curses.color_pair(random.randrange(1,7)))
+ # Let's pick a random color!
+ self.scr.attrset(curses.color_pair(random.randrange(1, 7)))
self.scr.addch(y+1, x+1, self.char)
self.scr.attrset(0)
self.scr.refresh()
# Birth
d[i,j] = 1
if curses.has_colors():
- #Let's pick a random color!
- self.scr.attrset(curses.color_pair(random.randrange(1,7)))
+ # Let's pick a random color!
+ self.scr.attrset(curses.color_pair(
+ random.randrange(1, 7)))
self.scr.addch(j+1, i+1, self.char)
self.scr.attrset(0)
if not live: self.boring = 0
self.state = d
self.scr.refresh()
- def makeRandom(self):
+ def make_random(self):
"Fill the board with a random pattern"
self.state = {}
for i in range(0, self.X):
if curses.has_colors():
stdscr.attrset(curses.color_pair(1))
stdscr.addstr(menu_y, 4,
- 'Use the cursor keys to move, and space or Enter to toggle a cell.')
+ 'Use the cursor keys to move, and space or Enter to toggle a cell.')
stdscr.addstr(menu_y+1, 4,
- 'E)rase the board, R)andom fill, S)tep once or C)ontinuously, Q)uit')
+ 'E)rase the board, R)andom fill, S)tep once or C)ontinuously, Q)uit')
stdscr.attrset(0)
def keyloop(stdscr):
xpos, ypos = board.X//2, board.Y//2
# Main loop:
- while (1):
+ while True:
stdscr.move(1+ypos, 1+xpos) # Move the cursor
c = stdscr.getch() # Get a keystroke
- if 0<c<256:
+ if 0 < c < 256:
c = chr(c)
if c in ' \n':
board.toggle(ypos, xpos)
# Activate nodelay mode; getch() will return -1
# if no keystroke is available, instead of waiting.
stdscr.nodelay(1)
- while (1):
+ while True:
c = stdscr.getch()
if c != -1:
break
- stdscr.addstr(0,0, '/')
+ stdscr.addstr(0, 0, '/')
stdscr.refresh()
board.display()
- stdscr.addstr(0,0, '+')
+ stdscr.addstr(0, 0, '+')
stdscr.refresh()
stdscr.nodelay(0) # Disable nodelay mode
elif c in 'Qq':
break
elif c in 'Rr':
- board.makeRandom()
+ board.make_random()
board.display(update_board=False)
elif c in 'Ss':
board.display()
else: pass # Ignore incorrect keys
- elif c == curses.KEY_UP and ypos>0: ypos -= 1
- elif c == curses.KEY_DOWN and ypos<board.Y-1: ypos += 1
- elif c == curses.KEY_LEFT and xpos>0: xpos -= 1
- elif c == curses.KEY_RIGHT and xpos<board.X-1: xpos += 1
+ elif c == curses.KEY_UP and ypos > 0: ypos -= 1
+ elif c == curses.KEY_DOWN and ypos < board.Y-1: ypos += 1
+ elif c == curses.KEY_LEFT and xpos > 0: xpos -= 1
+ elif c == curses.KEY_RIGHT and xpos < board.X-1: xpos += 1
elif c == curses.KEY_MOUSE:
- (mouse_id, mouse_x, mouse_y, mouse_z, button_state) = curses.getmouse()
- if (mouse_x>0 and mouse_x<board.X+1) and (mouse_y>0 and mouse_y<board.Y+1):
+ mouse_id, mouse_x, mouse_y, mouse_z, button_state = curses.getmouse()
+ if (mouse_x > 0 and mouse_x < board.X+1 and
+ mouse_y > 0 and mouse_y < board.Y+1):
xpos = mouse_x - 1
ypos = mouse_y - 1
board.toggle(ypos, xpos)
def main(stdscr):
keyloop(stdscr) # Enter the main loop
-
if __name__ == '__main__':
curses.wrapper(main)
-#! /usr/bin/env python3
+#!/usr/bin/env python3
+
+"""
+Markov chain simulation of words or characters.
+"""
class Markov:
def __init__(self, histsize, choice):
#!/usr/bin/env python3
-#
-# Send/receive UDP multicast packets.
-# Requires that your OS kernel supports IP multicast.
-#
-# Usage:
-# mcast -s (sender, IPv4)
-# mcast -s -6 (sender, IPv6)
-# mcast (receivers, IPv4)
-# mcast -6 (receivers, IPv6)
+
+"""
+Send/receive UDP multicast packets.
+Requires that your OS kernel supports IP multicast.
+
+Usage:
+ mcast -s (sender, IPv4)
+ mcast -s -6 (sender, IPv6)
+ mcast (receivers, IPv4)
+ mcast -6 (receivers, IPv6)
+"""
MYPORT = 8123
MYGROUP_4 = '225.0.0.250'
-#! /usr/bin/env python3
+#!/usr/bin/env python3
-"""N queens problem.
+"""
+N queens problem.
The (well-known) problem is due to Niklaus Wirth.
This solution is inspired by Dijkstra (Structured Programming). It is
a classic recursive backtracking approach.
-
"""
N = 8 # Default; command line overrides
-#! /usr/bin/env python3
+#!/usr/bin/env python3
-# Remote python client.
-# Execute Python commands remotely and send output back.
+"""
+Remote python client.
+Execute Python commands remotely and send output back.
+"""
import sys
from socket import socket, AF_INET, SOCK_STREAM, SHUT_WR
-#! /usr/bin/env python3
+#!/usr/bin/env python3
-# Remote python server.
-# Execute Python commands remotely and send output back.
-# WARNING: This version has a gaping security hole -- it accepts requests
-# from any host on the Internet!
+"""
+Remote python server.
+Execute Python commands remotely and send output back.
+
+WARNING: This version has a gaping security hole -- it accepts requests
+from any host on the Internet!
+"""
import sys
from socket import socket, AF_INET, SOCK_STREAM
-#! /usr/bin/env python3
+#!/usr/bin/env python3
-"""Sorting algorithms visualizer using Tkinter.
+"""
+Sorting algorithms visualizer using Tkinter.
This module is comprised of three ``components'':
- and a ``driver'' class which can be used as a Grail applet or as a
stand-alone application.
-
"""
from tkinter import *
import random
-
XGRID = 10
YGRID = 10
WIDTH = 6
-"""SS1 -- a spreadsheet."""
+#!/usr/bin/env python3
+
+"""
+SS1 -- a spreadsheet-like application.
+"""
import os
import re
+#!/usr/bin/env python3
+
+"""
+A demonstration of classes and their special methods in Python.
+"""
+
class Vec:
- """ A simple vector class
+ """A simple vector class.
- Instances of the Vec class can be constructed from numbers
+ Instances of the Vec class can be constructed from numbers
>>> a = Vec(1, 2, 3)
>>> b = Vec(3, 2, 1)
useful while building, extending or managing Python. Some (e.g., dutree or lll)
are also generally useful UNIX tools.
-See also the Demo/scripts directory!
-
2to3 Main script for running the 2to3 conversion tool
analyze_dxp.py Analyzes the result of sys.getdxp()
byext.py Print lines/words/chars stats of files by extension
projects / thirdparty / Python / cpython.git / commitdiff
