Adds support for multigraphs

[jackboyla]

hello again👋 adding support for multigraphs this time

from grandcypher import GrandCypher
import networkx as nx

host = nx.MultiDiGraph()
host.add_node("a", name="Alice", age=30)
host.add_node("b", name="Bob", age=40)
host.add_node("c", name="Charlie", age=50)
host.add_edge("a", "b", __labels__={"friend"}, years=3)
host.add_edge("a", "c", __labels__={"colleague"}, years=10)
host.add_edge("a", "c", __labels__={"parent"}, duration='forever')
host.add_edge("b", "c", __labels__={"colleague"}, duration=10)
host.add_edge("b", "c", __labels__={"mentor"}, years=2)

qry = """
MATCH (a)-[r]->(b)
RETURN a.name, b.name, r.__labels__, r.duration
"""
res = GrandCypher(host).run(qry)
print(res)

'''
{'a.name': ['Alice', 'Alice', 'Bob'], 
'b.name': ['Bob', 'Charlie', 'Charlie'], 
'r.__labels__': [{0: {'friend'}}, {0: {'colleague'}, 1: {'parent'}}, {0: {'colleague'}, 1: {'mentor'}}], 
'r.duration': [{0: None}, {0: None, 1: 'forever'}, {0: 10, 1: None}]}
'''

This implementation deviates from standard Cypher in the output, as it provides nested relations + relation attributes e.g
GrandCypher returns:

{'a.name': ['Alice', 'Alice', 'Bob'], 
'b.name': ['Bob', 'Charlie', 'Charlie'], 
'r.__labels__': [{0: {'friend'}}, {0: {'colleague'}, 1: {'parent'}}, {0: {'colleague'}, 1: {'mentor'}}], 
'r.duration': [{0: None}, {0: None, 1: 'forever'}, {0: 10, 1: None}]}

when Neo4j returns the expanded version:

{'a.name': ['Alice', 'Alice', 'Alice ,'Bob', 'Bob'], 
'b.name': ['Bob', 'Charlie', 'Charlie', 'Charlie', 'Charlie'], 
'r.__labels__': [{0: {'friend'}}, {0: {'colleague'}}, {0: {'parent'}}, {0: {'colleague'}}, {0: {'mentor'}}], 
'r.duration': [{0: None}, {0: None}, {0: 'forever'}, {0: 10}, {0: None}]}

[jackboyla]

bump 😇 @j6k4m8

[j6k4m8]

sorry @jackboyla -- just getting back from vacation today!

this is SO awesome and totally will be a force-multiplier for this library! doing some testing locally on this right now and will report back!

[jackboyla]

no problem! 😁

[j6k4m8]

This is so great, really thoughtful implementation!

[j6k4m8]

Amazing @jackboyla, LGTM! (I'll add you to the changelog/readme "thanks" if you don't do it yourself! ;) )

[jackboyla]

Cheers @j6k4m8 ! glad I could help😊