mirror of https://github.com/python/cpython
56 lines
1.3 KiB
Python
56 lines
1.3 KiB
Python
# Brownian motion -- an example of a NON multi-threaded Tkinter program ;)
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# By Michele Simoniato, inspired by brownian.py
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from tkinter import *
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import random
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import sys
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WIDTH = 400
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HEIGHT = 300
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SIGMA = 10
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BUZZ = 2
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RADIUS = 2
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LAMBDA = 10
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FILL = 'red'
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stop = 0 # Set when main loop exits
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root = None # main window
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def particle(canvas): # particle = iterator over the moves
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r = RADIUS
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x = random.gauss(WIDTH/2.0, SIGMA)
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y = random.gauss(HEIGHT/2.0, SIGMA)
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p = canvas.create_oval(x-r, y-r, x+r, y+r, fill=FILL)
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while not stop:
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dx = random.gauss(0, BUZZ)
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dy = random.gauss(0, BUZZ)
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try:
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canvas.move(p, dx, dy)
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except TclError:
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break
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else:
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yield None
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def move(particle): # move the particle at random time
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particle.next()
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dt = random.expovariate(LAMBDA)
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root.after(int(dt*1000), move, particle)
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def main():
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global root, stop
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root = Tk()
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canvas = Canvas(root, width=WIDTH, height=HEIGHT)
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canvas.pack(fill='both', expand=1)
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np = 30
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if sys.argv[1:]:
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np = int(sys.argv[1])
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for i in range(np): # start the dance
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move(particle(canvas))
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try:
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root.mainloop()
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finally:
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stop = 1
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if __name__ == '__main__':
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main()
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