def join(data, strategy, source_left, source_right, destination, key_left,
key_right, prefix_left, prefix_right, presorted, buffersize, tempdir,
cache, missing):
"""Perform a join on two data tables."""
source_left = data.get(source_left)
source_right = data.get(source_right)
kwargs = {}
if key_left == key_right:
kwargs['key'] = key_left
else:
kwargs['lkey'] = key_left
kwargs['rkey'] = key_right
if presorted is True:
kwargs['presorted'] = presorted
if buffersize is not None:
kwargs['buffersize'] = buffersize
if tempdir:
kwargs['tempdir'] = tempdir
if 'anti' not in strategy:
if prefix_left is not None:
kwargs['lprefix'] = prefix_left
if prefix_right is not None:
kwargs['rprefix'] = prefix_right
if strategy not in ['join', 'antijoin', 'hashjoin', 'hashantijoin']:
kwargs['missing'] = missing
if strategy == 'join':
o = petl.join(source_left, source_right, **kwargs)
elif strategy == 'leftjoin':
o = petl.leftjoin(source_left, source_right, **kwargs)
elif strategy == 'lookupjoin':
o = petl.lookupjoin(source_left, source_right, **kwargs)
elif strategy == 'rightjoin':
o = petl.rightjoin(source_left, source_right, **kwargs)
elif strategy == 'outerjoin':
o = petl.outerjoin(source_left, source_right, **kwargs)
elif strategy == 'antijoin':
o = petl.antijoin(source_left, source_right, **kwargs)
elif strategy == 'hashjoin':
o = petl.antijoin(source_left, source_right, **kwargs)
elif strategy == 'hashleftjoin':
o = petl.hashleftjoin(source_left, source_right, **kwargs)
elif strategy == 'hashlookupjoin':
o = petl.hashlookupjoin(source_left, source_right, **kwargs)
elif strategy == 'hashrightjoin':
o = petl.hashrightjoin(source_left, source_right, **kwargs)
data.set(destination, o)
def join_execute(cl, cr, join, **kwargs):
cl, cr = cl(), cr()
if 'addLfields' in kwargs:
cl = etl.addfields(cl, kwargs['addLfields'])
if 'addRfields' in kwargs:
cr = etl.addfields(cr, kwargs['addRfields'])
args = cl, cr
if join == Join.UNION:
c = etl.crossjoin(*args)
else:
kwargs = filter_keys(kwargs,
("key", "lkey", "rkey", "missing", "presorted",
"buffersize", "tempdir", "cache"))
if join == Join.INNER:
c = etl.join(*args, **kwargs)
elif join == Join.LEFT:
c = etl.leftjoin(*args, **kwargs)
elif join == Join.RIGHT:
c = etl.rightjoin(*args, **kwargs)
elif join == Join.FULL:
c = etl.outerjoin(*args, **kwargs)
return c
# rightjoin
table1 = [['id', 'colour'],
[1, 'blue'],
[2, 'red'],
[3, 'purple']]
table2 = [['id', 'shape'],
[1, 'circle'],
[3, 'square'],
[4, 'ellipse']]
from petl import rightjoin, look
look(table1)
look(table2)
table3 = rightjoin(table1, table2, key='id')
look(table3)
# outerjoin
table1 = [['id', 'colour'],
[1, 'blue'],
[2, 'red'],
[3, 'purple']]
table2 = [['id', 'shape'],
[1, 'circle'],
[3, 'square'],
[4, 'ellipse']]
from petl import outerjoin, look
# rightjoin
table1 = [['id', 'colour'],
[1, 'blue'],
[2, 'red'],
[3, 'purple']]
table2 = [['id', 'shape'],
[1, 'circle'],
[3, 'square'],
[4, 'ellipse']]
from petl import rightjoin, look
look(table1)
look(table2)
table3 = rightjoin(table1, table2, key='id')
look(table3)
# outerjoin
table1 = [['id', 'colour'],
[1, 'blue'],
[2, 'red'],
[3, 'purple']]
table2 = [['id', 'shape'],
[1, 'circle'],
[3, 'square'],
[4, 'ellipse']]
from petl import outerjoin, look
# leftjoin() ############ import petl as etl table1 = [['id', 'colour'], [1, 'blue'], [2, 'red'], [3, 'purple']] table2 = [['id', 'shape'], [1, 'circle'], [3, 'square'], [4, 'ellipse']] table3 = etl.leftjoin(table1, table2, key='id') table3 # rightjoin() ############# import petl as etl table1 = [['id', 'colour'], [1, 'blue'], [2, 'red'], [3, 'purple']] table2 = [['id', 'shape'], [1, 'circle'], [3, 'square'], [4, 'ellipse']] table3 = etl.rightjoin(table1, table2, key='id') table3 # outerjoin() ############# import petl as etl table1 = [['id', 'colour'], [1, 'blue'], [2, 'red'], [3, 'purple']] table2 = [['id', 'shape'], [1, 'circle'], [3, 'square'], [4, 'ellipse']] table3 = etl.outerjoin(table1, table2, key='id') table3 # crossjoin() ############# import petl as etl
table3
# rightjoin()
#############
import petl as etl
table1 = [['id', 'colour'],
[1, 'blue'],
[2, 'red'],
[3, 'purple']]
table2 = [['id', 'shape'],
[1, 'circle'],
[3, 'square'],
[4, 'ellipse']]
table3 = etl.rightjoin(table1, table2, key='id')
table3
# outerjoin()
#############
import petl as etl
table1 = [['id', 'colour'],
[1, 'blue'],
[2, 'red'],
[3, 'purple']]
table2 = [['id', 'shape'],
[1, 'circle'],
[3, 'square'],
[4, 'ellipse']]
