toying with OrientDB to build a genre graph from a YAML file

main.py

import pyorient
import yaml
import os, sys, codecs

def cp65001(name):
    if name.lower()=='cp65001':
        return codecs.lookup('utf-8')

codecs.register(cp65001)
os.environ["PYTHONIOENCODING"] = "cp65001"

c = pyorient.OrientDB("localhost", 2424)  # host, port
c.connect("guilherme", "guilherme")
try:
    c.db_drop("multimedia")
except:
    pass
c.db_create("multimedia", pyorient.DB_TYPE_GRAPH, pyorient.STORAGE_TYPE_MEMORY)
c.db_open("multimedia", "guilherme", "guilherme")


def createV(cli, name, extends=u'V'):
    cli.command("create class {} extends {}".format(name, extends))

def insert(client=c, cls='Genre', x=''):
    c.record_create(11,{'@Genre': { 'name': x}})

def select(x):
    x = repr(x.replace("'","\\'"))
    return "select * from Genre where name={}".format(x)

def all():
    createV(c, "Genre")
    createV(c, "is_subgenre_of", "E")

    genres = set()
    relationships = set()

    def relationship(x, y, r='is_subgenre_of'):
        return "CREATE EDGE {}".format(r) + " from (" + select(x) + ") to (" +select(y)+ ")" if x else ''

    def do(data, x=u'', depth=1):
        if isinstance(data, list):
            for ls in data:
                # List of genres
                if isinstance(ls, str):
                    #
                    # print("[INFO] list >> str")
                    #
                    # print("genre: {}".format(ls))
                    #
                    genre = ls
                    genres.add(genre)
                    genres.add(x)
                    # print(relationship(x, genre))
                    relationships.add(relationship(x, genre))

                # List of dicts
                elif isinstance(ls, dict):
                    #
                    # print("[INFO] list >> dict")
                    #
                    genres.add(x)
                    do(ls, x, ++depth)

                else:
                    #
                    print("[INFO] ??????")
                    #
                    # do(ls, x, ++depth)

        # Dict
        elif isinstance(data, dict):
            for key, val in data.items():
                #
                # print("[INFO] dict >> key val")
                #
                # print ("[INFO] " + str(depth) + ": " + str(key))

                if isinstance(val, list):
                    depth += 1
                    for item in data:
                        if (relationship(x, item) != ''):
                            # print(relationship(x, item))
                            relationships.add(relationship(x, item))
                            genres.add(item)

                        do(val, x=key, depth=depth)

                elif isinstance(data, str):
                    print(relationship(x, data))

    with open("genres-tree.yaml", 'r', encoding='utf-8') as stream:
        try:
            a = yaml.load(stream)
            do(a)
        except yaml.YAMLError as exc:
            print(exc)

    def x():
        # db.command("INSERT INTO Genre SET name = 'continental jazz'")
        for item in genres:
            insert(c, "Genre", item)
            # print ("db.command(\"INSERT INTO Genre Set name = '{}'\")".format(item))
    x()

    for item in relationships:
        print(item)
        c.command(item)

if __name__ == "__main__":
    all()