I have tried to establish a connection using this simple python example, and I get the error - py2neo.errors.ServiceUnavailable: Cannot connect to any known routers

Please help

from py2neo import Graph, Node, Relationship

g = Graph("<my db>", auth=("neo4j", "<my password>")) # replace with your own credentials

#tx = g.begin()

a = Node("Person", name="Alice")

g.create(a)

b = Node("Person", name="Bob")

ab = Relationship(a, "KNOWS", b)

g.create(ab)

g.commit()

g.exists(ab)