Django Comparison

Here are some common queries, showing how they’re done in Django vs Piccolo. All of the Piccolo examples can also be run asynchronously.

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Queries

get

They are very similar, except Django raises an ObjectDoesNotExist exception if no match is found, whilst Piccolo returns None.

# Django
>>> Band.objects.get(name="Pythonistas")
<Band: 1>
>>> Band.objects.get(name="DOESN'T EXIST")  # ObjectDoesNotExist!

# Piccolo
>>> Band.objects().get(Band.name == 'Pythonistas').run_sync()
<Band: 1>
>>> Band.objects().get(Band.name == "DOESN'T EXIST").run_sync()
None

get_or_create

# Django
band, created = Band.objects.get_or_create(name="Pythonistas")
>>> band
<Band: 1>
>>> created
True

# Piccolo
>>> band = Band.objects().get_or_create(Band.name == 'Pythonistas').run_sync()
>>> band
<Band: 1>
>>> band._was_created
True

create

# Django
>>> band = Band(name="Pythonistas")
>>> band.save()
>>> band
<Band: 1>

# Piccolo
>>> band = Band(name="Pythonistas")
>>> band.save().run_sync()
>>> band
<Band: 1>

update

# Django
>>> band = Band.objects.get(name="Pythonistas")
>>> band
<Band: 1>
>>> band.name = "Amazing Band"
>>> band.save()

# Piccolo
>>> band = Band.objects().get(Band.name == 'Pythonistas').run_sync()
>>> band
<Band: 1>
>>> band.name = "Amazing Band"
>>> band.save().run_sync()

delete

Individual rows:

# Django
>>> band = Band.objects.get(name="Pythonistas")
>>> band.delete()

# Piccolo
>>> band = Band.objects().get(Band.name == 'Pythonistas').run_sync()
>>> band.remove().run_sync()

In bulk:

# Django
>>> Band.objects.filter(popularity__lt=1000).delete()

# Piccolo
>>> Band.delete().where(Band.popularity < 1000).run_sync()

filter

# Django
>>> Band.objects.filter(name="Pythonistas")
[<Band: 1>]

# Piccolo
>>> Band.objects().where(Band.name == "Pythonistas").run_sync()
[<Band: 1>]

values_list

# Django
>>> Band.objects.values_list('name')
[{'name': 'Pythonistas'}, {'name': 'Rustaceans'}]

# Piccolo
>>> Band.select(Band.name).run_sync()
[{'name': 'Pythonistas'}, {'name': 'Rustaceans'}]

With flat=True:

# Django
>>> Band.objects.values_list('name', flat=True)
['Pythonistas', 'Rustaceans']

# Piccolo
>>> Band.select(Band.name).output(as_list=True).run_sync()
['Pythonistas', 'Rustaceans']

select_related

Django has an optimisation called select_related which reduces the number of SQL queries required when accessing related objects.

# Django
band = Band.objects.get(name='Pythonistas')
>>> band.manager  # This triggers another db query
<Manager: 1>

# Django, with select_related
band = Band.objects.select_related('manager').get(name='Pythonistas')
>>> band.manager  # Manager is pre-cached, so there's no extra db query
<Manager: 1>

Piccolo has something similar:

# Piccolo
band = Band.objects(Band.manager).get(Band.name == 'Pythonistas').run_sync()
>>> band.manager
<Manager: 1>

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Schema

OneToOneField

To do this in Piccolo, use a ForeignKey with a unique constraint - see One to One.

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Database settings

In Django you configure your database in settings.py. With Piccolo, you define an Engine in piccolo_conf.py. See Engines.

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Creating a new project

With Django you use django-admin startproject mysite.

In Piccolo you use piccolo asgi new (see ASGI).