Multithreaded SQLite Python

multithreaded_sqlite.py

from threading import Thread
from multiprocessing import Queue
import sqlite3, sys, time, datetime

class MultiThreadOK(Thread):
	def __init__(self, db):
		super(MultiThreadOK, self).__init__()
		self.db=db
		self.reqs=Queue()
		self.start()
	def run(self):
		cnx = sqlite3.Connection(self.db) 
		cursor = cnx.cursor()
		while True:
			req = self.reqs.get()
			if req=='--close--': break
			elif req=='--commit--': cnx.commit()
			try:
				cursor.executescript(req) if ';' in req else cursor.execute(req)
			except sqlite3.OperationalError as err:
				self.escribir_error('{0} - Error {1}\n'.format(datetime.datetime.now(), err))
				self.escribir_error('{0} - {1}\n'.format(datetime.datetime.now(), req))
			except:
				self.escribir_error('{0} - Salida'.format(datetime.datetime.now()))
		cnx.close()
	def execute(self, req):
		self.reqs.put(req)
	def queries(self):
		return self.reqs.qsize()
	def empty(self):
		return self.reqs.empty()
	def select(self, req, results=0):
		cnx = sqlite3.Connection(self.db)
		cursor = cnx.cursor()
		try:
			if results == 0:
				cursor.execute(req)
				ret = [x for x in cursor.fetchall()]
				cnx.close()
				return 	ret
			else:
				cursor.execute(req)
				ret = [x for x in cursor.fetchall()[:results]]
				cnx.close()
				return 	ret
		except:
			print("Unexpected error: {0}".format(sys.exc_info()[0]))
			cnx.close()
	def commit(self):
		self.execute("--commit--")
	def close(self):
		self.execute('--close--')
	def escribir_error(self, texto):
		with open(os.path.dirname(os.path.abspath(__file__)) + '\\errores.txt','a') as archivo:
			archivo.write(texto)


if __name__=='__main__':
    db='people.db'
    sql=MultiThreadOK(db)
    sql.execute("create table people(name,first)")
    sql.execute("insert into people (name,first) values('Czabania','George')")
    sql.commit()
    sql.execute("insert into people (name,first) values('Cooper','Jono')")
    sql.commit()
    sql.execute("insert into people (name,first) values('Wick','John');insert into people values('Anderson','Thomas');")
    sql.commit()
    #much more efficient way to do bulk Inserts and Updates to the DB
    sql.execute("BEGIN TRANSACTION;INSERT INTO people (name,first) values ('Smith','John');INSERT INTO people values ('Anderson','Thomas');COMMIT;")
    for q in sql.select("select * from people"):
        print(q)
    #wait until all write are done to read all updated data
    while sql.queries() > 0:
        time.sleep(5)
    sql.close()