Collections

This page show the type of collections qjoin is able to merge together.

The elements of a collection must respect 2 constraints. Each element must be a container and each element must contain the join key.

Collection of dictionnary

A dictionary collection can be used both as a base collection and as a join collection.

spacecrafts = [
    {'name': 'Kepler', 'cospar_id': '2009-011A', 'satcat': 34380},
    {'name': 'GRAIL (A)', 'cospar_id': '2011-046', 'satcat': 37801},
    {'name': 'InSight', 'cospar_id': '2018-042a', 'satcat': 43457},
    {'name': 'lucy', 'cospar_id': '2021-093A', 'satcat': 49328},
    {'name': 'Psyche', 'cospar_id': None, 'satcat': None},
]

Dictionaries in the same collection can have a variable number of keys, provided that the join key is always present.

spacecrafts_mission_infos = [
    {'name': 'Kepler', 'mission_type': 'Space telescope', 'launch_date':'2009-03-07T03:49Z', 'end_of_mission': '2018-11-15'},
    {'name': 'GRAIL (A)', 'launch_date':'2011-09-10T13:08Z', 'end_of_mission': '2012-12-17'},
    {'name': 'InSight', 'mission_type': 'Mars lander', 'launch_date':'2018-05-05T11:05Z', 'end_of_mission': '2022-12-21'},
    {'name': 'lucy', 'mission_type': 'Multiple-flyby of asteroids', 'launch_date':'2021-10-16T09:34Z'},
]

global_space_crafts = qjoin.on(spacecrafts).join(spacecrafts_mission_infos, key='name').all()
for spacecraft, spacecraft_mission_infos in global_space_crafts:
    print(spacecraft['name'])

Collection of tuple

A tuple collection can be used as both a base collection and a join collection.

spacecrafts = [
    ('Kepler', '2009-011A', 34380),
    ('GRAIL (A)', '2011-046', 37801),
    ('InSight', '2018-042a', 43457),
    ('lucy', '2021-093A', 49328),
    ('Psyche', None, None),
]

global_space_crafts = qjoin.on(spacecrafts).join(spacecrafts_properties, left=0, right='name').all()
for spacecraft, spacecraft_properties in global_space_crafts:
    print(spacecraft[0])

Collection of list

A list collection can be used as both a base collection and a join collection.

spacecrafts = [
    ['Kepler', '2009-011A', 34380],
    ['GRAIL (A)', '2011-046', 37801],
    ['InSight', '2018-042a', 43457],
    ['lucy', '2021-093A', 49328],
    ['Psyche', None, None],
]

global_space_crafts = qjoin.on(spacecrafts).join(spacecrafts_properties, left=0, right='name').all()
for spacecraft, spacecraft_properties in global_space_crafts:
    print(spacecraft[0])

Collection of objects

A collection of objects can be used both as a base collection and as a join collection.

class Spacecraft:
    def __init__(self, name, cospar_id, satcat):
        self.name = name
        self.cospar_id = cospar_id
        self.satcat = satcat

spacecrafts = [
    Spacecraft('Kepler', '2009-011A', 34380),
    Spacecraft('GRAIL (A)', '2011-046', 37801),
    Spacecraft('InSight', '2018-042a', 43457),
    Spacecraft('lucy', '2021-093A', 49328),
    Spacecraft('Psyche', None, None),
]

global_space_crafts = qjoin.on(spacecrafts).join(spacecrafts_properties, left='name', right='name').all()
for spacecraft, spacecraft_properties in global_space_crafts:
    print(spacecraft.name)

Note

qjoin supporte les collections d’objets qui viennent d’ORM comme sqlalchemy ou django.