如何在Django URL模式中使用十进制数？

Question

I'd like to use a number with a decimal point in a Django URL pattern but I'm not sure whether it's actually possible (I'm not a regex expert).

Here's what I want to use for URLs:

/item/value/0.01
/item/value/0.05

Those URLs would show items valued at $0.01 or $0.05. Sure, I could take the easy way out and pass the value in cents so it would be /item/value/1, but I'd like to receive the argument in my view as a decimal data type rather than as an integer (and I may have to deal with fractions of a cent at some point). Is it possible to write a regex in a Django URL pattern that will handle this?

Answer 1

It can be something like

urlpatterns = patterns('',
   (r'^item/value/(?P<value>\d+\.\d{2})/$', 'myapp.views.byvalue'),
   ... more urls
)

url should not start with slash.

in views you can have function:

def byvalue(request,value='0.99'):
    try:
        value = float(value)
    except:
        ...

Answer 2

我不知道Django具体，但这应该匹配URL：

r"^/item/value/(\d+\.\d+)$"

Answer 3

如果要接受的值仅为0.01美元或0.05美元，则可以像下面这样指定harto的模式：

r"^/item/value/(\d\.\d{2})$"

Answer 4

Don't use »

url(r"^item/value/(?P<dollar>\d+\.\d{1,2})$", views.show_item, name="show-item"),

It will only match the URL patterns like /item/value/0.01 , /item/value/12.2 etc.

It won't match URL patterns like /item/value/1.223 , /item/value/1.2679 etc.

Better is to use »

url(r"^item/value/(?P<dollar>\d+\.\d+)$", views.show_item, name="show-item"),

It will match URL patterns like /item/value/0.01 , /item/value/1.22 , /item/value/10.223 , /item/value/1.3 etc.

Finally you can design your views.py something like

This is just for an example.

# Make sure you have defined Item model (this is just an example)
# You use your own model name
from .models import Item 

def show_item(request, dollar):
    try:
        # Convert dollar(string) to dollar(float).
        # Which gets passed to show_item() if someone requests 
        # URL patterns like /item/value/0.01, /item/value/1.22 etc.
        dollar = float(dollar);

        # Fetch item from Database using its dollar value
        # You may use your own strategy (it's mine)
        item = Item.objects.get(dollar=dollar);

        # Make sure you have show_item.html.
        # Pass item to show_item.html (Django pawered page) so that it could be 
        # easily rendered using DTL (Django template language).
        return render(request, "show_item.html", {"item": item});
    except:
        # Make sure you have error.html page (In case if there's an error)
        return render(request, "error.html", {});