Django – zobbo.org

Python – comparing floats and decimals

By zobbo | 18 December 2011 by zobbo

No matter how old I get, I keep being bitten by the joys of having some data as floats and some as decimals. [cc lang=”python”] ipdb> value Decimal(‘1.473’) ipdb> from_value 1.473 ipdb> value < from_value True [/cc] because ... [cc lang="python"] ipdb> from decimal import * ipdb> Decimal(from_value) Decimal(‘1.4730000000000000870414851306122727692127227783203125’) [/cc] So work out what accuracy you need and do something like [cc lang=”python”] from_value = Decimal(from_value).quantize(Decimal(‘0.0001’)) [/cc]

Staticfiles in Django 1.3 not working?

By zobbo | 22 August 2011 by zobbo

Wasted a lot of time on this today when I shouldn’t have done. If you find that your staticfiles in Django are just not working for you, when the docs say they should be, try this. The docs say here that: “This view is automatically enabled and will serve your static files at STATIC_URL when you use the built-in runserver management command.” Well, it doesn’t work for me. As per the example after I had…

Converting Legacy Databases to Django – Day 0.5 to 1.5

By zobbo | 19 August 2011 by zobbo

Second part of this project. You can read the first part here.

Django/Postgresql – inserting new record doesn’t return id.

By zobbo | 19 August 2011 by zobbo

You have an old database and you find the following happens. [cc lang=”python”] >>> ap = ValidAirPressureCode(code=’9′, description=’9′, barcode=’9′, comments=’ 9′) >>> ap.save() >>> ap.id >>> ap = ValidAirPressureCode.objects.get(code=’9′) >>> ap.id 11 [/cc] In short Django doesn’t return the id of a newly inserted record. If you insert records in admin and choose to continue editing, you’ll get an error saying it can’t find a record with a null id. The problem (in my case)…

Converting Legacy Databases to Django 1.3 – Day 0.5

By zobbo | 18 August 2011 by zobbo

I have done this quite a few times in the past, but not recently. I was given three days to convert an existing postgres database (front ended with Zope) to Django 1.3. I thought it would be useful to document what I did here for my own future reference and to record any gotchas for posterity. The database I am converting is nine years old, so plenty of cruft through the years, although the basic…