prices
module
django-prices: Django fields for the
Installation
pip install django-prices
- Add
django_prices
to yourINSTALLED_APPS
atsettings.py
- Follow
enmerkar
instructions and update both yourINSTALLED_APPS
andMIDDLEWARE_CLASSES
.
Features
Provides support for models:
from django.db import models
from django_prices.models import MoneyField, TaxedMoneyField
class Model(models.Model):
currency = models.CharField(max_length=3, default="BTC")
price_net_amount = models.DecimalField(max_digits=9, decimal_places=2, default="5")
price_net = MoneyField(amount_field="price_net_amount", currency_field="currency")
price_gross_amount = models.DecimalField(
max_digits=9, decimal_places=2, default="5"
)
price_gross = MoneyField(
amount_field="price_gross_amount", currency_field="currency"
)
price = TaxedMoneyField(
net_amount_field="price_net_amount",
gross_amount_field="price_gross_amount",
currency="currency",
)
And forms:
from django import forms
from django_prices.forms import MoneyField
AVAILABLE_CURRENCIES = ["BTC", "USD"]
class ProductForm(forms.Form):
name = forms.CharField(label="Name")
price_net = MoneyField(label="net", available_currencies=AVAILABLE_CURRENCIES)
And validators:
from django import forms
from prices.forms import Money
from django_prices.forms import MoneyField
from django_prices.validators import (
MaxMoneyValidator, MinMoneyValidator, MoneyPrecisionValidator)
class DonateForm(forms.Form):
donator_name = forms.CharField(label="Your name")
donation = MoneyField(
label="net",
available_currencies=["BTC", "USD"],
max_digits=9,
decimal_places=2,
validators=[
MoneyPrecisionValidator(),
MinMoneyValidator(Money(5, "USD")),
MaxMoneyValidator(Money(500, "USD")),
],
)
It also provides support for templates:
{% load prices %}
<p>Price: {{ foo.price.gross|amount }} ({{ foo.price.net|amount }} + {{ foo.price.tax|amount }} tax)</p>
You can also use HTML output from prices
template tags, they will wrap currency symbol in a <span>
element:
{% load prices %}
<p>Price: {{ foo.price.gross|amount:'html' }} ({{ foo.price.net|amount:'html' }} + {{ foo.price.tax|amount:'html' }} tax)</p>
It will be rendered as a following structure (for example with English locale):
<span class="currency">$</span>15.00
How to migrate to django-prices 2.0
Version 2.0 introduces major changes to how prices data is stored in models, enabling setting price's currency per model instance.
Steps to migrate:
-
In your forms:
- remove the
currency
argument - add
available_currencies
with available choices.
If the form specified
MoneyFields
infields
option, replace those with explicit declarations instead:AVAILABLE_CURRENCIES = [("BTC", "bitcoins"), ("USD", "US dollar")] class ModelForm(forms.ModelForm): class Meta: model = models.Model fields = [] price_net = MoneyField(available_currencies=AVAILABLE_CURRENCIES)
- remove the
-
In your models using
MoneyField
:-
Replace all occurrences of the
MoneyField
class withDecimalField
-
Remove the
currency
argument from them -
Change
default
from Money instance to value acceptable by Decimal fieldExample of code:
price_net = MoneyField( "net", currency="BTC", default=Money("5", "BTC"), max_digits=9, decimal_places=2 )
Updated code:
price_net = models.DecimalField("net", default="5", max_digits=9, decimal_places=2)
-
-
In your migration files:
-
Replace all occurrences of the
MoneyField
class withDecimalField
-
Remove the
currency
argument from them -
Change
default
from Money instance to value acceptable by Decimal fieldfield = django_prices.models.MoneyField(currency='BTC', decimal_places=2, default='5', max_digits=9, verbose_name='net')
Updated code:
field = models.DecimalField(decimal_places=2, default='5', max_digits=9, verbose_name='net')
-
-
Rename fields in models. Your old field will still store amount of money, so probably the best choice would be
price_net_amount
insteadprice_net
. -
All places which use Models and it's fields can prevent django app from even starting the code. Possible issues: code tries to access non existing fields. Exclude those fields for now from your ModelForms, Graphene types etc.
-
Run
python manage.py makemigrations
. Make sure to do this step before adding newMoneyFields
to model! If not, django will generatedelete/create
migrations instead ofrename
. -
Run
python manage.py migrate
. -
Update
django-prices
. -
Add
models.CharField
for currency andMoneyField
to your models:currency = models.CharField(max_length=3, default="BTC") price_net_amount = models.DecimalField("net", default="5", max_digits=9, decimal_places=2) price_net = MoneyField(amount_field="price_net_amount", currency_field="currency")
-
Run
python manage.py makemigrations
andpython manage.py migrate
. -
Change
TaxedMoneyField
declaration:price = TaxedMoneyField( net_amount_field="price_net_amount", gross_amount_field="price_gross_amount", currency="currency", )
-
Remember to address changes in previously edited ModelForms