First create a client instance with your credentials:
>>> import ceilometerclient.client
>>> cclient = ceilometerclient.client.get_client(VERSION, username=USERNAME, password=PASSWORD, tenant_name=PROJECT_NAME, auth_url=AUTH_URL)
Here VERSION can be: 1 and 2.
Then call methods on its managers:
>>> cclient.meters.list()
[<Meter ...>, ...]
>>> cclient.samples.list()
[<Sample ...>, ...]
Use queries to narrow your search (more info at Ceilometer V2 API reference):
>>> query = [dict(field='resource_id', op='eq', value='5a301761-f78b-46e2-8900-8b4f6fe6675a')]
>>> ceilometer.samples.list(meter_name='cpu_util', limit=10, q=query)
[<Sample ...>, ...]
For more information, see the reference: