Django views.py Lookup value from constant list

Question

In a django views.py how do you take a selection (number) from input can get the matching "Description"? For example the user selects 3 and returns "Yellow"

colors = [
    ('0','black'),
    ('1','white'),
    ('2','Red'),
    ('3','Yellow'),
    ('4','Blue'),
    ('5','Green')
    ]

...

colorSelection = form.cleaned_data.get('color')

#lookup color description
colorDescription = ???

Answer 1

You will need to make a dictionary, or at least something to look up the description, so:

COLORS = [
    ('0', 'black'),
    ('1', 'white'),
    ('2', 'Red'),
    ('3', 'Yellow'),
    ('4', 'Blue'),
    ('5', 'Green'),
]

# …

colorSelection = form.cleaned_data.get('color')
colorDescription = dict(COLORS).get(colSelection)

Since django-3.0 however, one often specifies these choices with a TextChoices instead, and this then makes a lookup more convenient:

class ColorChoices(models.TextChoices):
    BLACK = '0', 'black'
    WHITE = '1', 'white'
    RED = '2', 'red'
    YELLOW = '3', 'yellow'
    BLUE = '4', 'blue'
    GREEN = '5', 'green'

Then we can look it up with:

ColorChoices(colSelection).label