code: def MonSQL(host=None, port=None, username=None, password=None, dbname=None, dbpath=None, dbtype=None):
  	
  	if dbtype is None:
  		raise MonSQLException('Database type must be specified')
  
  	if dbtype == DB_TYPES.MYSQL:
  		return MySQLDatabase(host, port, username, password, dbname)
  	elif dbtype == DB_TYPES.SQLITE3:
  		return SQLite3Database(dbpath)
  	elif dbtype == DB_TYPES.POSTGRESQL:
  		return PostgreSQLDatabase(host, port, username, password, dbname)
  	else:
  		raise MonSQLException('Database type %s not supported' %dbtype)
docs: Initialize and return a Database instance