mirror of https://github.com/python/cpython
92 lines
2.3 KiB
Python
Executable File
92 lines
2.3 KiB
Python
Executable File
#! /usr/bin/env python
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# Simulate "electrons" migrating across the screen.
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# An optional bitmap file in can be in the background.
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#
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# Usage: electrons [n [bitmapfile]]
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#
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# n is the number of electrons to animate; default is 30.
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#
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# The bitmap file can be any X11 bitmap file (look in
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# /usr/include/X11/bitmaps for samples); it is displayed as the
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# background of the animation. Default is no bitmap.
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from tkinter import *
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import random
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# The graphical interface
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class Electrons:
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# Create our objects
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def __init__(self, n, bitmap = None):
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self.n = n
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self.tk = tk = Tk()
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self.canvas = c = Canvas(tk)
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c.pack()
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width, height = tk.getint(c['width']), tk.getint(c['height'])
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# Add background bitmap
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if bitmap:
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self.bitmap = c.create_bitmap(width/2, height/2,
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bitmap=bitmap,
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foreground='blue')
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self.pieces = []
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x1, y1, x2, y2 = 10,70,14,74
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for i in range(n):
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p = c.create_oval(x1, y1, x2, y2, fill='red')
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self.pieces.append(p)
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y1, y2 = y1 +2, y2 + 2
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self.tk.update()
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def random_move(self, n):
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c = self.canvas
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for p in self.pieces:
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x = random.choice(range(-2,4))
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y = random.choice(range(-3,4))
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c.move(p, x, y)
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self.tk.update()
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# Run -- allow 500 movemens
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def run(self):
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try:
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for i in range(500):
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self.random_move(self.n)
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except TclError:
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try:
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self.tk.destroy()
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except TclError:
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pass
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# Main program
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def main():
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import sys, string
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# First argument is number of electrons, default 30
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if sys.argv[1:]:
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n = string.atoi(sys.argv[1])
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else:
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n = 30
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# Second argument is bitmap file, default none
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if sys.argv[2:]:
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bitmap = sys.argv[2]
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# Reverse meaning of leading '@' compared to Tk
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if bitmap[0] == '@': bitmap = bitmap[1:]
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else: bitmap = '@' + bitmap
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else:
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bitmap = None
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# Create the graphical objects...
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h = Electrons(n, bitmap)
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# ...and run!
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h.run()
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# Call main when run as script
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if __name__ == '__main__':
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main()
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