Top-level collections

The launchpad web service’s top-level collections provide access to Launchpad-wide objects like projects and people.

>>> import httplib2
>>> httplib2.debuglevel = 1

>>> from launchpadlib.testing.helpers import salgado_with_full_permissions
>>> launchpad = salgado_with_full_permissions.login()
send: ...
...

It’s possible to do key-based lookups on the top-level collections. The bug collection does lookups by bug ID.

>>> bug = launchpad.bugs[1]
send: b'GET /.../bugs/1 ...'
...

To avoid triggering an HTTP request when simply looking up an object, you can use a different syntax:

>>> bug = launchpad.bugs(1)

The HTTP request will happen when you need information that can only be obtained from the web service.

>>> print(bug.id)
send: b'GET /.../bugs/1 ...'
...
1

Let’s look at some more collections. The project collection does lookups by project name.

>>> project = launchpad.projects('firefox')
>>> print(project.name)
send: b'GET /.../firefox ...'
...
firefox

The project group collection does lookups by project group name.

>>> group = launchpad.project_groups('gnome')
>>> print(group.name)
send: b'GET /.../gnome ...'
...
gnome

The distribution collection does lookups by distribution name.

>>> distribution = launchpad.distributions('ubuntu')
>>> print(distribution.name)
send: b'GET /.../ubuntu ...'
...
ubuntu

The person collection does lookups by a person’s Launchpad name.

>>> person = launchpad.people('salgado')
>>> print(person.name)
send: b'GET /.../~salgado ...'
...
salgado

>>> team = launchpad.people('rosetta-admins')
>>> print(team.name)
send: b'GET /1.0/~rosetta-admins ...'
...
rosetta-admins

How does launchpadlib know that ‘salgado’ is a person and ‘rosetta-admins’ is a team?

>>> print(person.resource_type_link)
http://.../1.0/#person
>>> 'default_membership_period' in person.lp_attributes
False

>>> print(team.resource_type_link)
http://.../1.0/#team
>>> 'default_membership_period' in team.lp_attributes
True

The truth is that it doesn’t know, not before making that HTTP request. Until an HTTP request is made, launchpadlib assumes everything in launchpad.people[] is a team (since a team has strictly more capabilities than a person).

>>> person2 = launchpad.people('salgado')
>>> 'default_membership_period' in person2.lp_attributes
True

But accessing any attribute of an object–even trying to see what kind of object ‘salgado’ is–will trigger the HTTP request that will determine that ‘salgado’ is actually a person.

>>> print(person2.resource_type_link)
send: b'GET /.../~salgado ...'
...
http://.../1.0/#person

>>> 'default_membership_period' in person2.lp_attributes
False

Accessing an attribute of an object that might be a team will trigger the HTTP request, and then cause an error if the object turns out not to be a team.

>>> person3 = launchpad.people('salgado')
>>> person3.default_membership_period
Traceback (most recent call last):
AttributeError: ...api.launchpad.../~salgado object has no attribute 'default_membership_period'

Cleanup.

>>> httplib2.debuglevel = 0