CODEWITHSUNDEEP
pythoncsvneo4jpy2neo
Owais Arshad
Owais Arshad

Reputation: 313

Creating Unique Node Relationships with Py2Neo from CSV

I have some data in csv format. Each row describes a relationship between two nodes. Nodes can have multiple relationships with other nodes, although there is only one relationship per row.

For example this is a relationship derived from one row in the csv:

(Entity1:Name {Type,Details})-[Relationship Type]->(Entity2:Name {Type,Details})

Entity1 could, on a different row be in the place of Entity2 and vice versa. Entity1 could also have relationships with Entity3 and Entity4 and so on although its type will never change.

Using Py2Neo I can import and create the relationships, but end up with loads of duplicate nodes for the entities. I want each Entity node to be unique.This is what I have:

def payload1(entity1,type1,relationtype,details_one,entity2,type2,details_two):
        graph = Graph("bolt://localhost:7687",auth=("Admin", "Password"))
        Entity1 = Node(type1,Name=entity1,Details=details_one)
        Entity2 = Node(type2,Name=entity2,Details=details_two)
        graph.create(Entity1)
        graph.create(Entity2)
        graph.create(Relationship(Entity1,relationtype,Entity2))




    df = pd.read_csv ('Data.csv')
    entities1 = df['Entity1'].tolist()
    types1 = df['Type'].tolist()
    relations1 = df['RelationType'].tolist()
    details1 = df['Details'].tolist()
    entity2 = df['Entity2'].tolist()
    types2 = df['Type2'].tolist()
    details_two = df['Details.1'].tolist()
    for (a, b, c,d,e,f,g) in itertools.zip_longest(entities1,types1,relations1,details1,entity2,types2,details_two):
        print (a, b, c,d,e,f,g)
        data = [((a,b,d),(c),(e,f,g))]
        keys = ["Name","Type","Details"]
        payload1(a,b,c,d,e,f,g)

Upvotes: 2

Views: 366

Answers (1)

jose_bacoy
jose_bacoy

Reputation: 12684

Instead of doing a create, do a merge. Simply put, merge will not create a duplicate node if it exists. Here is the documentation about it:

Reference: https://py2neo.org/v4/_modules/py2neo/database.html#Transaction.merge

For each node, the merge is carried out by comparing that node with a potential remote equivalent on the basis of a single label and property value. If no remote match is found, a new node is created; if a match is found, the labels and properties of the remote node are updated.

OLD code:
    graph.create(Entity1) 

NEW code:
    graph.merge(Entity1)

Upvotes: 1

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