SQlite WAL-mode in python. Concurrency with one writer and one reader -

i'm trying share sqlite3 database between 1 writer process, , 1 reader process. however, not work, , seems me nothing being written in example.db.

reader.py

import sqlite3 time import sleep conn = sqlite3.connect('example.db', isolation_level=none)  c = conn.cursor() while true:     c.execute("select * statistics")     try:         print '**'         print c.fetchone()     except:         pass     sleep(3) 

writer.py

import sqlite3 time import sleep import os  if os.path.exists('example.db'):     os.remove('example.db')  conn = sqlite3.connect('example.db', isolation_level=none) c = conn.cursor() c.execute('pragma journal_mode=wal') print c.fetchone() c.execute("create table statistics (stat1 real, stat2 real)")  stat1 = 0 stat2 = 0.0 while true:     stat1 += 1     stat2 += 0.1     cmd = "insert statistics values (%d,%f)" % (stat1, stat2)     print cmd     c.execute(cmd)     #conn.commit()     c.execute("pragma wal_checkpoint=full")     sleep(0.25) 

i run writer.py in background process, , run reader.py. shows:

** (1.0, 0.1) ** (1.0, 0.1) ** (1.0, 0.1) 

(...)

what correct (and best) way set framework 1 reader , 1 writer?

what expect? select first row of table. , same row. "pragma"-statements have no visible effects here.