Using a tuple as function arguments

Question

For this function I can use tuple elements as arguments:

light_blue = .6, .8, .9
gradient.add_color_rgb(0, *light_blue)

What if i have to add another argument after the tuple?

light_blue = .6, .8, .9
alpha = .5
gradient.add_color_rgba(0, *light_blue, alpha)

does not work. What does work is

gradient.add_color_rgba(0, *list(light_blue)+[alpha])

which does not really look better than

gradient.add_color_rgba(0, light_blue[0], light_blue[1], light_blue[2], alpha)

Is there a better way to do this?

Daniel Kluev · Accepted Answer · 2010-07-31 10:27:44Z

6

You could call it like gradient.add_color_rgba(0, *light_blue, alpha=alpha) if you know parameter name for the alpha.

answered Jul 31, 2010 at 10:27

Daniel Kluev

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Comments

mikej · Accepted Answer · 2010-07-31 10:28:51Z

2

You can simplify the expression slightly by making a tuple instead of a list containing light_blue and alpha e.g.

gradient.add_color_rgba(0, *(light_blue + (alpha,)))

answered Jul 31, 2010 at 10:28

mikej

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Depending on light_blue type is quite nasty. IMO it's better to assume that it's any iterable.

Ok now i remember this is the way to create a one-element tuple.