Re: [Neo4j] Python Newbie Struggling Slightly
Tom, I just installed the python bindings and tried this very simple setup to create a database and populate it within a transaction: #!/usr/bin/env python import sys, random, csv from time import sleep from random import randint import neo4j graphdb = neo4j.GraphDatabase(db) with graphdb.transaction: person = graphdb.node(name=Person) peter = graphdb.node(name=Peter) peter.IS_A(person) print peter['name'] graphdb.shutdown() If you try this, is that working for you? Cheers, /peter neubauer COO and Sales, Neo Technology GTalk: neubauer.peter Skype peter.neubauer Phone +46 704 106975 LinkedIn http://www.linkedin.com/in/neubauer Twitter http://twitter.com/peterneubauer http://www.neo4j.org - Your high performance graph database. http://www.thoughtmade.com - Scandinavia's coolest Bring-a-Thing party. On Tue, Jul 27, 2010 at 5:25 PM, Tom Smith tas...@york.ac.uk wrote: Hello, I really like the look of neo4j and would like to use it in a project I'm working on http://pppeoplepppowered.blogspot.com/ . I'm new to graphs and how to work with them, it's all new, but really drawn to them having banged my head on SQL schemas for years (and years). My problem with working with python neo4j is that there aren't enough simple (enough) examples. This is sort of thing is great ... http://blog.neo4j.org/2010/03/modeling-categories-in-graph-database.html ... but it doesn't explain a few things and goes wrong in places. For example, from the example, if I try to execute... computers_node = graphdb.node(Name=Computers) ... I get... jpype._jexception.RuntimeExceptionPyRaisable: org.neo4j.graphdb.NotInTransactionException: No transaction found for current thread So I need to add... with db.transaction: computers_node = graphdb.node(Name=Computers) ... which raises the issue of transactions and database connections. I'm unsure when to use transactions and how to use connections. Either way, I regularly seem to bump into a... jpype._jexception.RuntimeExceptionPyRaisable: org.neo4j.kernel.impl.transaction.TransactionFailureException: Could not create data source [nioneodb], see nested exception for cause of error Because I like to use the interpreter and learn what objects can do, and later create .py files and import them. It's not clear if I can have more than one db connection open at once, or I should open and shutdown the database everytime... or is it better to have one database connection hanging around in a file somewhere? At the moment I'm trying to create a script that, takes a csv file of people, adds them, then tries to get the data out somehow, like this... import stuff.neo_utils as neo # see below neo.import_people() #import a csv 7051 #the id of the root_person neo.people(7051) #get the people out via the root_person #nothing! neo.people(8224) # the id of the last_person Node id=7051 My question is this... am I doing it all wrong? Could someone create a very simple example that say, populates a graph, gets data out, manipulates that data and then searches that data (say for an attribute, or to see if it exists etc) in a single python file? So that I can begin to build up my understanding, thanks for listening, tom #!/usr/bin/env python import sys, random, csv from time import sleep from random import randint import neo4j class Person(neo4j.Traversal): types = [ neo4j.Outgoing.is_a ] order = neo4j.BREADTH_FIRST stop = neo4j.STOP_AT_END_OF_GRAPH returnable = neo4j.RETURN_ALL_BUT_START_NODE def people(person_root_id ): try:graphdb.shutdown() except:pass graphdb = neo4j.GraphDatabase( neo_db ) with graphdb.transaction: person_root = graphdb.node[person_root_id] for person_node in Person(person_root): try: print %s %s (@depth=%s) % ( person_node['family_name'], person_node['email'],person_node.depth) except: print person_node graphdb.shutdown( ) # The data is like this... #tas...@york.ac.uk Staff Mr T Smith |Computing Service: | |Vanbrugh College V/C/011| |+44 1904 433847| https://www.york.ac.uk/directory/user.yrk/searchdetail.cfm?scope=staffref=M95%27%22%3DYBD8%5B%3ANEJ%27S%27I%2AX%20%20F%2D6Y2%3D%20SR%21A%409%2C%40E2%3D%205%2EFMOM6A%3A%3EWIHV4T%5D%5E%3B%0A%2B4%2D%2A%3EG%2D%2F6EUS%22BI0%20%0Areferrer=searchResults def import_people(name=Untitled, file='/Users/tomsmith/pppeoplepppowered/staff/staff.csv', ): 'load a lot of people into the database, connecting each to a root Person object by a is_a relationship, spurious I know ' graphdb = neo4j.GraphDatabase( neo_db ) with graphdb.transaction: person_root = graphdb.node(name=Person) # create a root node of sorts person_root_id = person_root.id csvReader = csv.reader(open(file), delimiter=' ', quotechar='|') for row in csvReader:
[Neo4j] Python Newbie Struggling Slightly
Hello, I really like the look of neo4j and would like to use it in a project I'm working on http://pppeoplepppowered.blogspot.com/ . I'm new to graphs and how to work with them, it's all new, but really drawn to them having banged my head on SQL schemas for years (and years). My problem with working with python neo4j is that there aren't enough simple (enough) examples. This is sort of thing is great ... http://blog.neo4j.org/2010/03/modeling-categories-in-graph-database.html ... but it doesn't explain a few things and goes wrong in places. For example, from the example, if I try to execute... computers_node = graphdb.node(Name=Computers) ... I get... jpype._jexception.RuntimeExceptionPyRaisable: org.neo4j.graphdb.NotInTransactionException: No transaction found for current thread So I need to add... with db.transaction: computers_node = graphdb.node(Name=Computers) ... which raises the issue of transactions and database connections. I'm unsure when to use transactions and how to use connections. Either way, I regularly seem to bump into a... jpype._jexception.RuntimeExceptionPyRaisable: org.neo4j.kernel.impl.transaction.TransactionFailureException: Could not create data source [nioneodb], see nested exception for cause of error Because I like to use the interpreter and learn what objects can do, and later create .py files and import them. It's not clear if I can have more than one db connection open at once, or I should open and shutdown the database everytime... or is it better to have one database connection hanging around in a file somewhere? At the moment I'm trying to create a script that, takes a csv file of people, adds them, then tries to get the data out somehow, like this... import stuff.neo_utils as neo # see below neo.import_people() #import a csv 7051 #the id of the root_person neo.people(7051) #get the people out via the root_person #nothing! neo.people(8224) # the id of the last_person Node id=7051 My question is this... am I doing it all wrong? Could someone create a very simple example that say, populates a graph, gets data out, manipulates that data and then searches that data (say for an attribute, or to see if it exists etc) in a single python file? So that I can begin to build up my understanding, thanks for listening, tom #!/usr/bin/env python import sys, random, csv from time import sleep from random import randint import neo4j class Person(neo4j.Traversal): types = [ neo4j.Outgoing.is_a ] order = neo4j.BREADTH_FIRST stop = neo4j.STOP_AT_END_OF_GRAPH returnable = neo4j.RETURN_ALL_BUT_START_NODE def people(person_root_id ): try:graphdb.shutdown() except:pass graphdb = neo4j.GraphDatabase( neo_db ) with graphdb.transaction: person_root = graphdb.node[person_root_id] for person_node in Person(person_root): try: print %s %s (@depth=%s) % ( person_node['family_name'], person_node['email'],person_node.depth) except: print person_node graphdb.shutdown( ) # The data is like this... #tas...@york.ac.uk Staff Mr T Smith |Computing Service: | |Vanbrugh College V/C/011| |+44 1904 433847| https://www.york.ac.uk/directory/user.yrk/searchdetail.cfm?scope=staffref=M95%27%22%3DYBD8%5B%3ANEJ%27S%27I%2AX%20%20F%2D6Y2%3D%20SR%21A%409%2C%40E2%3D%205%2EFMOM6A%3A%3EWIHV4T%5D%5E%3B%0A%2B4%2D%2A%3EG%2D%2F6EUS%22BI0%20%0Areferrer=searchResults def import_people(name=Untitled, file='/Users/tomsmith/pppeoplepppowered/staff/staff.csv', ): 'load a lot of people into the database, connecting each to a root Person object by a is_a relationship, spurious I know ' graphdb = neo4j.GraphDatabase( neo_db ) with graphdb.transaction: person_root = graphdb.node(name=Person) # create a root node of sorts person_root_id = person_root.id csvReader = csv.reader(open(file), delimiter=' ', quotechar='|') for row in csvReader: email = row[0] kind = row[1] title = row[2] given_name = row[3] family_name = row[4] department = row[5] org_path = row[6] full_address = row[7] telephone = row[8] src = row[9] url = row[10] external_url = row[11] person = graphdb.node(email=email,title=title, given_name=given_name,family_name=family_name, telephone=telephone,department=department, org_path=org_path,src=src, url=url, external_url=external_url) person.is_a( person_root ) print person, created and linked print done importing! graphdb.shutdown( ) return person_root_id ___
