How to enclose a tuple in quotation marks to use it as string argument in a function?

Question

Challenge

How do I get from (255, 255, 255, 0) to '(255, 255, 255, 0)' when the former is a tuple?

Details:

I'm converting hex colors to rgba colors using an approach described here. I'm doing this to use the color as arguments with an opacity element like so:

color = 'rgba(255, 255, 255, 0)'

As you might already have guessed, the argument has to be of a string type. And I've come so far as having the integers in a tuple like so

(255, 255, 255, 0)

Now I need to enclose the whole tuple in a string like '(255, 255, 255, 0)' to get to my last step:

'rgba(255, 255, 255, 0)'

I'm afraid I'm missing some obvious and very fundamental element of Python here, but any suggestions would be great!

`'rgba({}, {}, {}, {})'.format(*your_tuple)` should do it, no? — Andrew, Apr 29 '20 at 11:57

Alexander Pushkarev · Answer 1 · 2020-04-29T12:21:09.887

6

I am afraid there's no simple conversion function for that, however, this should work:

t = (255, 255, 255, 0)
f'rgba({t[0]}, {t[1]}, {t[2]}, {t[3]})'

Even shorter:

t = (255, 255, 255, 0)
f'rgba{str(t)}'

Depending on the context, I would probably prefer the first option for two reasons:

second option, while shorter, depends on the str implementation for tuples. It is unlikely to change, but unlikely does not mean impossible
(the most important) it just accidentally occurred that str view for tuples fits the expected string pattern. Once string pattern changes it may be a nightmare bug to trace and fix.

The first option explicitly separates representation from data, and also allows us to use any iterable, not only tuples. And using a class instead of the tuple, in this case, may be a very robust idea.

edited Apr 29 '20 at 12:21

answered Apr 29 '20 at 11:59

Alexander Pushkarev

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I've submitted an answer on this thread, but I must admit that your last solution is beautifully elegant. – Jake Tae Apr 29 '20 at 12:04
@JST99 Thank you! Honestly, I would usually prefer the first option, as it would not depend on str implementation staying the same – Alexander Pushkarev Apr 29 '20 at 12:11

score 3 · Accepted Answer · answered Apr 29 '20 at 11:58

3

How about casting it in str?

>>> color = (255, 255, 255, 0)
>>> str(color)
'(255, 255, 255, 0)'
>>> str_color = 'rgba' + str(color)
>>> str_color
'rgba(255, 255, 255, 0)'

answered Apr 29 '20 at 11:58

Jake Tae

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score 3 · Answer 3 · answered Apr 29 '20 at 11:59

3

You should be able to use string formatting and tuple unpacking for this:

your_tuple = (255, 255, 255, 0)
'rgba({}, {}, {}, {})'.format(*your_tuple)

answered Apr 29 '20 at 11:59

Andrew

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score 2 · Answer 4 · answered Apr 29 '20 at 11:58

2

Simply str((255, 255, 255, 0))

>>> a = (255, 255, 255, 0)
>>> type(a)
<class 'tuple'>
>>> b = str(a)
>>> print(b, type(b))
(255, 255, 255, 0) <class 'str'>

answered Apr 29 '20 at 11:58

Sid

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How to enclose a tuple in quotation marks to use it as string argument in a function?

4 Answers4