CODEWITHSUNDEEP
djangopython-3.xdjango-models
Arthur Choate
Arthur Choate

Reputation: 533

Django model is truncating a decimal place when passed to the view when DecimalField is set

Django Model: 

class TwoDecimal(models.Model):
   two_decimal = models.DecimalField(decimal_places=2, max_digits=10)

View:

def two_decimal(request):
    test = TwoDecimal(
        two_decimal = 30.00
    )
    test.save()
    return render(
        request,
        "test-template.html",
        {"test": test}
    )

Template: 

{{ test.two_decimal }}  #==> Displays as 30.0 instead of 30.00 (Despite it being a two decimal field.)

This displays properly if it is a query from already saved data.

Why is django truncating this decimal place?

Upvotes: 1

Views: 382

Answers (1)

willeM_ Van Onsem
willeM_ Van Onsem

Reputation: 477684

You should pass it a decimal, right now you pass it a float. The fact that it is then saved in a DecimalField does not make the attribute a Decimal. If you would later retrieve it, then it indeed will be retrieved as a decimal.

from decimal import Decimal

def two_decimal(request):
    test = TwoDecimal(
        two_decimal = Decimal('30.00')
    )
    test.save()
    return render(
        request,
        'test-template.html',
        {'test': test}
    )

Note that it is important to pass the value as a string to the Decimal constructor. Otherwise it might introduce small rounding errors, and furthermore it does no longer contain information about the number of digits.

Upvotes: 1

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