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891a1f86d4
The 'wikipedia' example is now 'rosette', describing what it draws. The 'penrose' print output is reduced. The 'tree' '1024' output is eliminated.
62 lines
1.4 KiB
Python
Executable file
62 lines
1.4 KiB
Python
Executable file
#!/usr/bin/env python3
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""" turtle-example-suite:
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tdemo_tree.py
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Displays a 'breadth-first-tree' - in contrast
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to the classical Logo tree drawing programs,
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which use a depth-first-algorithm.
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Uses:
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(1) a tree-generator, where the drawing is
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quasi the side-effect, whereas the generator
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always yields None.
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(2) Turtle-cloning: At each branching point
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the current pen is cloned. So in the end
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there are 1024 turtles.
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"""
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from turtle import Turtle, mainloop
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from time import perf_counter as clock
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def tree(plist, l, a, f):
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""" plist is list of pens
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l is length of branch
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a is half of the angle between 2 branches
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f is factor by which branch is shortened
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from level to level."""
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if l > 3:
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lst = []
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for p in plist:
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p.forward(l)
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q = p.clone()
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p.left(a)
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q.right(a)
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lst.append(p)
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lst.append(q)
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for x in tree(lst, l*f, a, f):
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yield None
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def maketree():
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p = Turtle()
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p.setundobuffer(None)
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p.hideturtle()
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p.speed(0)
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p.getscreen().tracer(30,0)
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p.left(90)
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p.penup()
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p.forward(-210)
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p.pendown()
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t = tree([p], 200, 65, 0.6375)
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for x in t:
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pass
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def main():
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a=clock()
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maketree()
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b=clock()
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return "done: %.2f sec." % (b-a)
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if __name__ == "__main__":
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msg = main()
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print(msg)
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mainloop()
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