Aggregation functions (COUNT, SUM, MIN, MAX, AVG)

[jackboyla]

Mentioned in #27 and #39 . Supports (COUNT, SUM, MIN, MAX, AVG).

There was also a small change that needed to be made for MultiDiGraphs, which should make it clearer which edge is being referred to in the results.

from grandcypher import GrandCypher
import networkx as nx

host = nx.MultiDiGraph()
host.add_node("a", name="Alice", age=25)
host.add_node("b", name="Bob", age=30)
host.add_edge("a", "b", __labels__={"paid"}, amount=12, date="12th June")
host.add_edge("b", "a", __labels__={"paid"}, amount=6)
host.add_edge("b", "a", __labels__={"paid"}, value=14)
host.add_edge("a", "b", __labels__={"friends"}, years=9)
host.add_edge("a", "b", __labels__={"paid"}, amount=40)

qry = """
MATCH (n)-[r:paid]->(m)
RETURN n.name, m.name, SUM(r.amount)
"""
res = GrandCypher(host).run(qry)
print(res)

'''
{
    'n.name': ['Alice', 'Bob'], 
    'm.name': ['Bob', 'Alice'], 
    'SUM(r.amount)': [{'paid': 52, 'friends': 0}, {'paid': 6}]
}
'''

Added more tests, and an examples page 😄

[j6k4m8]

WOOHOOOOOO! This is so great @jackboyla! I'll review this asap!!

[j6k4m8]

Incredible — going to merge this and roll to PyPI today!! Thank you again @jackboyla!! Making some awesome contributions :)

[jackboyla]

awesome! it’s a pleasure🤗