Sqlite3 isolation_level and savepoint suport test

Console result

[3/4.3.17]niwi@vaio:~> python2 savepoint_sqlite3_test.py
python version: 2.7.3 (default, Apr 24 2012, 00:00:54) 
[GCC 4.7.0 20120414 (prerelease)]
PySQLite version: 2.6.0
sqlite3 version: 3.7.13


Test with isolation_level = None (autocommit mode)
**********************************************************************
ROW: (0, 200)
ROW: (5, 205)

Test with isolation_level =  (default) and use_savepoint = False
**********************************************************************
Traceback (most recent call last):
  File "savepoint_sqlite3_test.py", line 63, in <module>
    for row in with_isolation_level(use_savepoint=False, isolation_level=""):
  File "savepoint_sqlite3_test.py", line 47, in with_isolation_level
    cur.execute("COMMIT")
OperationalError: cannot commit - no transaction is active

Test with isolation_level =  (default) and use_savepoint = False
**********************************************************************
Traceback (most recent call last):
  File "savepoint_sqlite3_test.py", line 72, in <module>
    for row in with_isolation_level(use_savepoint=True, isolation_level=""):
  File "savepoint_sqlite3_test.py", line 33, in with_isolation_level
    cur.execute("rollback to savepoint spTest;")
OperationalError: no such savepoint: spTest

savepoint_test.py

# -*- coding: utf-8 -*-
import sys
import sqlite3
import traceback

print 'python version:', sys.version
print 'PySQLite version:', sqlite3.version
print 'sqlite3 version:', sqlite3.sqlite_version
print

def with_isolation_level(isolation_level="", use_savepoint=False):
    conn = sqlite3.connect(':memory:')
    conn.isolation_level = isolation_level

    cur = conn.cursor()

    cur.execute("create table example (A, B);")

    # With isolation_level != None this is redundant, because
    # sqlite3 module executes this implicitly, and sqlite3 ignores this.
    cur.execute("BEGIN")

    cur.execute("insert into example values (?, ?);", (0,200))

    if use_savepoint:
        cur.execute("savepoint spTest;")

    cur.execute("insert into example values (?, ?);", (1,201))
    cur.execute("insert into example values (?, ?);", (2,202))

    if use_savepoint:
        # see COMMIT commet
        cur.execute("rollback to savepoint spTest;")

    cur.execute("insert into example values (?, ?);", (5,205))

    # On isolation_level != None, the explicitly BEGIN statements are ignored
    # and on intent execute this, raises: "OperationalError: cannot commit - no transaction is active"
    # beacause the explicitly BEGIN transaction are not tracked.

    # ```By default, the sqlite3 module opens transactions implicitly before a Data Modification Language
    # (DML) statement (i.e. INSERT/UPDATE/DELETE/REPLACE), and commits transactions implicitly before a
    # non-DML, non-query statement (i. e. anything other than SELECT or the aforementioned).```
    # SOURCE: http://docs.python.org/library/sqlite3.html#controlling-transactions

    # Same behavior is for savepoints, only works on isolation_level == None
    cur.execute("COMMIT")

    cur.execute("select * from example;")
    return list(cur)



print "\nTest with isolation_level = None (autocommit mode)"
print "*"*70
for row in with_isolation_level(use_savepoint=True, isolation_level=None):
    print "ROW:", row


print "\nTest with isolation_level = "" (default) and use_savepoint = False"
print "*"*70
try:
    for row in with_isolation_level(use_savepoint=False, isolation_level=""):
        print "ROW:", row
except Exception:
    traceback.print_exc()


print "\nTest with isolation_level = "" (default) and use_savepoint = False"
print "*"*70
try:
    for row in with_isolation_level(use_savepoint=True, isolation_level=""):
        print "ROW:", row
except Exception:
    traceback.print_exc()