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Ben Finney ben+python at benfinney.id.au
Thu Oct 9 03:42:14 CEST 2014


Seymore4Head <Seymore4Head at Hotmail.invalid> writes:

> I want to toggle between color="Red" and color="Blue"

It's good to cultivate ongoing familiarity with the standard library
<URL:https://docs.python.org/3/library/itertools.html#itertools.cycle>
so that you can make use of wheels already invented and maintained::

    import itertools

    colours = ["Red", "Blue"]
    colour_cycle = itertools.cycle(colours)

    next(colour_cycle)    # → "Red"
    next(colour_cycle)    # → "Blue"
    next(colour_cycle)    # → "Red"
    next(colour_cycle)    # → "Blue"
    next(colour_cycle)    # → "Red"

    for colour in colour_cycle:
        # … loops indefinitely
        # with ‘colour’ bound to each value in turn …

-- 
 \      “My roommate got a pet elephant. Then it got lost. It's in the |
  `\                              apartment somewhere.” —Steven Wright |
_o__)                                                                  |
Ben Finney




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