old_contents: import os, sys
  import sqlite3
  from pkg_resources import resource_string
  
  class DBError(Exception):
      pass
  
  def get_schema(version):
      return resource_string("wormhole", "db-schemas/v%d.sql" % version)
  
  def get_db(dbfile, stderr=sys.stderr):
      """Open or create the given db file. The parent directory must exist.
      Returns the db connection object, or raises DBError.
      """
  
      must_create = not os.path.exists(dbfile)
      try:
          db = sqlite3.connect(dbfile)
      except (EnvironmentError, sqlite3.OperationalError) as e:
          raise DBError("Unable to create/open db file %s: %s" % (dbfile, e))
      db.row_factory = sqlite3.Row
  
      VERSION = 1
      if must_create:
          schema = get_schema(VERSION)
          db.executescript(schema)
          db.execute("INSERT INTO version (version) VALUES (?)", (VERSION,))
          db.commit()
  
      try:
          version = db.execute("SELECT version FROM version").fetchone()[0]
      except sqlite3.DatabaseError as e:
          # this indicates that the file is not a compatible database format.
          # Perhaps it was created with an old version, or it might be junk.
          raise DBError("db file is unusable: %s" % e)
  
      if version != VERSION:
          raise DBError("Unable to handle db version %s" % version)
  
      return db
  
new_contents: import os, sys
  import sqlite3
  from pkg_resources import resource_string
  
  class DBError(Exception):
      pass
  
  def get_schema(version):
      schema_bytes = resource_string("wormhole", "db-schemas/v%d.sql" % version)
      return schema_bytes.decode("utf-8")
  
  def get_db(dbfile, stderr=sys.stderr):
      """Open or create the given db file. The parent directory must exist.
      Returns the db connection object, or raises DBError.
      """
  
      must_create = not os.path.exists(dbfile)
      try:
          db = sqlite3.connect(dbfile)
      except (EnvironmentError, sqlite3.OperationalError) as e:
          raise DBError("Unable to create/open db file %s: %s" % (dbfile, e))
      db.row_factory = sqlite3.Row
  
      VERSION = 1
      if must_create:
          schema = get_schema(VERSION)
          db.executescript(schema)
          db.execute("INSERT INTO version (version) VALUES (?)", (VERSION,))
          db.commit()
  
      try:
          version = db.execute("SELECT version FROM version").fetchone()[0]
      except sqlite3.DatabaseError as e:
          # this indicates that the file is not a compatible database format.
          # Perhaps it was created with an old version, or it might be junk.
          raise DBError("db file is unusable: %s" % e)
  
      if version != VERSION:
          raise DBError("Unable to handle db version %s" % version)
  
      return db
  
subject: make py3-compatible