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While using the Routing solver of the google or-tools,a runtime error is thrown. There was a no changes made in the code segment,before and after getting this error. Previously, it was working. But recently after a DB connection modification was made, I am getting this error.
(Although, I doubt how a dB connection modification could affect the routing solver)
I am using the Azure Databricks notebook. As I am new to operations research, I have taken the example given in the https://developers.google.com/optimization/routing/pickup_delivery#complete_programs page, as my reference.
This is Vehicle Routing with Pick and Delivery problem.
from __future__ import print_function
from ortools.constraint_solver import routing_enums_pb2
from ortools.constraint_solver import pywrapcp
def create_data_model():
"""Stores the data for the problem."""
data = {}
data['distance_matrix'] = dist
data['pickups_deliveries'] = nodes_pickup_delivery
data['num_vehicles'] = 2
data['depot'] = 0
return data
solution_list = []
def print_solution(data, manager, routing, assignment):
"""Prints assignment on console."""
total_distance = 0
for vehicle_id in range(data['num_vehicles']):
index = routing.Start(vehicle_id)
plan_output = 'Route for vehicle {}:\n'.format(vehicle_id)
route_distance = 0
i = []
while not routing.IsEnd(index):
i.append(manager.IndexToNode(index))
plan_output += ' {} -> '.format(str(cityList[manager.IndexToNode(index)]))
previous_index = index
index = assignment.Value(routing.NextVar(index))
route_distance += routing.GetArcCostForVehicle(previous_index, index, vehicle_id)
solution_list.append(i)
plan_output += '{}\n'.format(str(cityList[manager.IndexToNode(index)]))
plan_output += 'Distance of the route: {} miles\n'.format(route_distance)
#print(plan_output)
total_distance += route_distance
#print('Total Distance of all routes: {} miles'.format(total_distance))
def main():
"""Entry point of the program."""
# Instantiate the data problem.
data = create_data_model()
# Create the routing index manager.
manager = pywrapcp.RoutingIndexManager(len(data['distance_matrix']), data['num_vehicles'], data['depot'])
# Create Routing Model.
routing = pywrapcp.RoutingModel(manager)
# Define cost of each arc.
def distance_callback(from_index, to_index):
"""Returns the manhattan distance between the two nodes."""
# Convert from routing variable Index to distance matrix NodeIndex.
from_node = manager.IndexToNode(from_index)
to_node = manager.IndexToNode(to_index)
return data['distance_matrix'][from_node][to_node]
transit_callback_index = routing.RegisterTransitCallback(distance_callback)
routing.SetArcCostEvaluatorOfAllVehicles(transit_callback_index)
# Add Distance constraint.
dimension_name = 'Distance'
routing.AddDimension(
transit_callback_index,
0, # no slack
40, # vehicle maximum travel distance
True, # start cumul to zero
dimension_name)
distance_dimension = routing.GetDimensionOrDie(dimension_name)
distance_dimension.SetGlobalSpanCostCoefficient(100)
# Define Transportation Requests.
for request in data['pickups_deliveries']:
pickup_index = manager.NodeToIndex(request[0])
delivery_index = manager.NodeToIndex(request[1])
routing.AddPickupAndDelivery(pickup_index, delivery_index)
routing.solver().Add(routing.VehicleVar(pickup_index) == routing.VehicleVar(delivery_index))
routing.solver().Add(distance_dimension.CumulVar(pickup_index) <= distance_dimension.CumulVar(delivery_index))
# Setting first solution heuristic.
search_parameters = pywrapcp.DefaultRoutingSearchParameters()
#search_parameters.time_limit.seconds = 90
search_parameters.first_solution_strategy = (routing_enums_pb2.FirstSolutionStrategy.PARALLEL_CHEAPEST_INSERTION)
# Solve the problem.
assignment = routing.SolveWithParameters(search_parameters)
# Print solution on console.
if assignment:
print_solution(data, manager, routing, assignment)
if __name__ == '__main__':
main()
The error I am getting is pointing to the following code segment: 'plan_output = 'Route for vehicle {}:\n'.format(vehicle_id)'
The error thrown is:
RuntimeError: SWIG std::function invocation failed.
RuntimeErrorTraceback (most recent call last)
<command-2714173895177597> in <module>()
89
90 if __name__ == '__main__':
---> 91 main()
<command-2714173895177597> in main()
85 # Print solution on console.
86 if assignment:
---> 87 print_solution(data, manager, routing, assignment)
88
89
<command-2714173895177597> in print_solution(data, manager, routing, assignment)
18 for vehicle_id in range(data['num_vehicles']):
19 index = routing.Start(vehicle_id)
---> 20 plan_output = 'Route for vehicle {}:\n'.format(vehicle_id)
21 route_distance = 0
22 i = []
RuntimeError: SWIG std::function invocation failed.
Kindly help.
def create_data_model():
"""Stores the data for the problem."""
data = {}
data['distance_matrix'] = dist
data['pickups_deliveries'] = nodes_pickup_delivery
data['num_vehicles'] = 2
data['depot'] = 0 #Dummy location
return data
solution_list = []
def print_solution(data, manager, routing, assignment):
"""Prints assignment on console."""
total_distance = 0
for vehicle_id in range(data['num_vehicles']):
index = routing.Start(vehicle_id)
plan_output = 'Route for vehicle {}:\n'.format(vehicle_id)
route_distance = 0
i = []
while not routing.IsEnd(index):
i.append(manager.IndexToNode(index))
plan_output += ' {} -> '.format(manager.IndexToNode(index))
previous_index = index
index = assignment.Value(routing.NextVar(index))
route_distance += routing.GetArcCostForVehicle(previous_index, index, vehicle_id)
solution_list.append(i)
plan_output += '{}({})\n'.format(str(cityList[manager.IndexToNode(index)]))
plan_output += 'Distance of the route: {} miles\n'.format(route_distance)
print(plan_output)
total_distance += route_distance
print('Total Distance of all routes: {} miles'.format(total_distance))
I am writing a script in python 3 that is listening to the tunnel and saving and updating data inside MySQL depend on the message received.
I went into weird behavior, i did a simple connection to MySQL using pymysql module and everything worked fine, ut after sometime this simple connection closes.
So i decide to implement Pool connection to MySQL and here arises the problem. Something happens no errors, but the issue is the following:
My cursor = yield self._pool.execute(query, list(filters.values()))
cursor result = tornado_mysql.pools.Pool object at 0x0000019DE5D71F98
and stacks like that not doing anything more
If i remove yield from cursor pass that line and next line throws error
response = yield c.fetchall()
AttributeError: 'Future' object has no attribute 'fetchall'
How i can fix the MySQL pool connection to work properly?
What i tried:
I use few modules for pool connection, all goes in same issue
Did back simple connection with pymysql and worked again
Below my code:
python script file
import pika
from model import SyncModel
_model = SyncModel(conf, _server_id)
#coroutine
def main():
credentials = pika.PlainCredentials('user', 'password')
try:
cp = pika.ConnectionParameters(
host='127.0.0.1',
port=5671,
credentials=credentials,
ssl=False,
)
connection = pika.BlockingConnection(cp)
channel = connection.channel()
#coroutine
def callback(ch, method, properties, body):
if 'messageType' in properties.headers:
message_type = properties.headers['messageType']
if message_type in allowed_message_types:
result = ptoto_file._reflection.ParseMessage(descriptors[message_type], body)
if result:
result = protobuf_to_dict(result)
if message_type == 'MyMessage':
yield _model.message_event(data=result)
else:
print('Message type not in allowed list = ' + str(message_type))
print('continue listening...')
channel.basic_consume(callback, queue='queue', no_ack=True)
print(' [*] Waiting for messages. To exit press CTRL+C')
channel.start_consuming()
except Exception as e:
print('Could not connect to host 127.0.0.1 on port 5671')
print(str(e))
if __name__ == '__main__':
main()
SyncModel
from tornado_mysql import pools
from tornado.gen import coroutine, Return
from tornado_mysql.cursors import DictCursor
class SyncModel(object):
def __init__(self, conf, server_id):
self.conf = conf
servers = [i for i in conf.mysql.servers]
for s in servers:
if s['server_id'] == server_id:
// s hold all data as, host, user, port, autocommit, charset, db, password
s['cursorclass'] = DictCursor
self._pool = pools.Pool(s, max_idle_connections=1, max_recycle_sec=3)
#coroutine
def message_event(self, data):
table_name = 'table_name'
query = ''
data = data['message']
filters = {
'id': data['id']
}
// here the connection fails as describe above
response = yield self.query_select(table_name, self._pool, filters=filters)
#coroutine
def query_select(self, table_name, _pool, filters=None):
if filters is None:
filters = {}
combined_filters = ['`%s` = %%s' % i for i in filters.keys()]
where = 'WHERE ' + ' AND '.join(combined_filters) if combined_filters else ''
query = """SELECT * FROM `%s` %s""" % (table_name, where)
c = self._pool.execute(query, list(filters.values()))
response = yield c.fetchall()
raise Return({response})
All the code was working with just simple connection to the database, after i start to use pool example is not working anymore. Will appreciate any help in this issue.
This is a stand alone script.
The pool connection was not working, so switched back to pymysql with double checking the connection
I would like to post my answer that worked, only this solution worked for me
before connecting to mysql to check if the connection is open, if not reconnect
if not self.mysql.open:
self.mysql.ping(reconnect=True)
So i have a program which will encrypt a string using AES and generate cipher which in bytes[].
I wish to store this cipher as it is in mysql database.
I found we could use VARBINARY data type in mysql to do so.
In what ways we could achieve so.
Here is my try to do so :
import ast
import mysql.connector
from Crypto.Cipher import AES
from Crypto.Random import get_random_bytes
def encrypt(key, msg):
iv = get_random_bytes(16)
cipher = AES.new(key, AES.MODE_CFB, iv)
ciphertext = cipher.encrypt(msg) # Use the right method here
db = iv + ciphertext
print(db)
cursor.executemany(sql_para_query,db)
print(cursor.fetchone())
connection.commit()
return iv + ciphertext
def decrypt(key, ciphertext):
iv = ciphertext[:16]
ciphertext = ciphertext[16:]
cipher = AES.new(key, AES.MODE_CFB, iv)
msg = cipher.decrypt(ciphertext)
return msg.decode("utf-8")
if __name__ == "__main__":
connection = mysql.connector.connect(host = "localhost", database = "test_db", user = "sann", password = "userpass",use_pure=True)
cursor = connection.cursor(prepared = True)
sql_para_query = """insert into test1 values(UNHEX(%s)) """
ed = input("(e)ncrypt or (d)ecrypt: ")
key = str(1234567899876543)
if ed == "e":
msg = input("message: ")
s= encrypt(key, msg)
print("Encrypted message: ", s)
file = open("e_tmp","wb+")
file.write(s)
print(type(s))
elif ed == "d":
#smsg = input("encrypted message: ")
#file = open("e_tmp","rb")
#smsg = file.read()
#print(type(smsg))
sql_para_query = """select * from test1"""
cursor.execute(sql_para_query)
row = cursor.fetchone()
print(row)
#smsg = str(smsg)
#msg = ast.literal_eval(smsg)
#print(msg)
#print(type(msg))
#s=decrypt(key, msg)
#print("Decrypted message: ", s)
#print(type(s))
Error I'm getting :
Traceback (most recent call last): File
"/home/mr_pool/.local/lib/python3.6/site-packages/mysql/connector/cursor.py",
line 1233, in executemany
self.execute(operation, params) File "/home/mr_pool/.local/lib/python3.6/site-packages/mysql/connector/cursor.py",
line 1207, in execute
elif len(self._prepared['parameters']) != len(params): TypeError: object of type 'int' has no len()
During handling of the above exception, another exception occurred:
Traceback (most recent call last): File "tmp1.py", line 36, in
s= encrypt(key, msg) File "tmp1.py", line 14, in encrypt
cursor.executemany(sql_para_query,db) File "/home/mr_pool/.local/lib/python3.6/site-packages/mysql/connector/cursor.py",
line 1239, in executemany
"Failed executing the operation; {error}".format(error=err)) mysql.connector.errors.InterfaceError: Failed executing the operation;
object of type 'int' has no len()
Any other alternatives are also welcome.
My ultimate goal is to store the encrypted text in database.
I reproduced your error, but it seems there are more errors in your code.
The key as well as the message are strings, therefore I got this error:
TypeError: Object type <class 'str'> cannot be passed to C code
Which I fixed by encoding them in utf-8:
# line 38:
key = str(1234567899876543).encode("utf8")
# .... line 41:
s= encrypt(key, msg.encode("utf8"))
The UNHEX function in your SQL Query is not needed because we are entering the data as VARBINARY. You can change your statement to:
"""insert into test1 values(%s) """
The function executemany() can be replaced by execute() because you are only entering one statement. However I will write the solution for using both, execute or executemany.
insert with execute():
From the documentation:
cursor.execute(operation, params=None, multi=False)
iterator = cursor.execute(operation, params=None, multi=True)
This method executes the given database operation (query or command). The parameters found in the tuple or dictionary params are bound to the variables in the operation. Specify variables using %s or %(name)s parameter style (that is, using format or pyformat style). execute() returns an iterator if multi is True.
https://dev.mysql.com/doc/connector-python/en/connector-python-api-mysqlcursor-execute.html
So we need just to build a tuple with your parameters by changing the cursor.execute line to:
cursor.execute(sql_para_query, (db, ))
insert with executemany():
From the documentation:
cursor.executemany(operation, seq_of_params)
This method prepares a database operation (query or command) and executes it against all parameter sequences or mappings found in the sequence seq_of_params.
https://dev.mysql.com/doc/connector-python/en/connector-python-api-mysqlcursor-executemany.html
Therefore we need to build a sequence with values you'd like to insert. In your case just one value:
cursor.executemany(sql_para_query, [(db, )])
To insert multiple values, you can add as many tuples into your sequence as you want.
full code:
import ast
import mysql.connector
from Crypto.Cipher import AES
from Crypto.Random import get_random_bytes
def encrypt(key, msg):
iv = get_random_bytes(16)
cipher = AES.new(key, AES.MODE_CFB, iv)
ciphertext = cipher.encrypt(msg) # Use the right method here
db = iv + ciphertext
cursor.execute(sql_para_query, (db, ))
connection.commit()
return iv + ciphertext
def decrypt(key, ciphertext):
iv = ciphertext[:16]
ciphertext = ciphertext[16:]
cipher = AES.new(key, AES.MODE_CFB, iv)
msg = cipher.decrypt(ciphertext)
return msg.decode("utf-8")
if __name__ == "__main__":
connection = mysql.connector.connect(host = "localhost", database = "test_db", user = "sann", password = "userpass",use_pure=True)
cursor = connection.cursor(prepared = True)
sql_para_query = """insert into test1 values(%s) """
ed = input("(e)ncrypt or (d)ecrypt: ")
key = str(1234567899876543).encode("utf8")
if ed == "e":
msg = input("message: ")
s= encrypt(key, msg.encode("utf8"))
print("Encrypted message: ", s)
file = open("e_tmp","wb+")
file.write(s)
print(type(s))
elif ed == "d":
sql_para_query = """select * from test1"""
cursor.execute(sql_para_query)
row = cursor.fetchone()
msg = row[0] # row is a tuple, therefore get first element of it
print("Unencrypted message: ", msg)
s=decrypt(key, msg)
print("Decrypted message: ", s)
output:
#encrypt:
(e)ncrypt or (d)ecrypt: e
message: this is my test message !!
Encrypted message: b"\x8f\xdd\xe6f\xb1\x8e\xb51\xc1'\x9d\xbf\xb5\xe1\xc7\x87\x99\x0e\xd4\xb2\x06;g\x85\xc4\xc1\xd2\x07\xb5\xc53x\xb9\xbc\x03+\xa2\x95\r4\xd1*"
<class 'bytes'>
#decrypt:
(e)ncrypt or (d)ecrypt: d
Unencrypted message: bytearray(b"\x8f\xdd\xe6f\xb1\x8e\xb51\xc1\'\x9d\xbf\xb5\xe1\xc7\x87\x99\x0e\xd4\xb2\x06;g\x85\xc4\xc1\xd2\x07\xb5\xc53x\xb9\xbc\x03+\xa2\x95\r4\xd1*")
Decrypted message: this is my test message !!
i have written a code to read registers of a modbus communication protocol. i have attached the code below as well.. am able to overcome the i/o errors by exception handling method where as the value error that i get , am not able throw that error and move on.
Basically what i am doing is am reading the data in the registers and sending up to the server. but my requirement is i have to read the values every second and for 24 hours. so i need to build a robust system that will overcome these value errors and continue executing the threads i have created.
the code to read registers is given below :
import minimalmodbus
import serial
from ctypes import *
import struct
import time
minimalmodbus.BAUDRATE = 9600
minimalmodbus.PARITY = serial.PARITY_NONE
minimalmodbus.BYTESIZE = 8
minimalmodbus.TIMEOUT=5
minimalmodbus.CLOSE_PORT_AFTER_EACH_CALL = True
energy_meter = serial.Serial("/dev/ttyUSB0", baudrate=9600,
parity=serial.PARITY_NONE,
stopbits=serial.STOPBITS_ONE, bytesize=serial.EIGHTBITS, timeout=5)
energy_meter = minimalmodbus.Instrument('/dev/ttyUSB0', 2, mode='rtu')
#energy_meter.debug = True
def convert_in_float(value1, value2):
raw = struct.pack('>HH',value1,value2)
ans = struct.unpack('>f', raw)[0]
return ans
def sdm630():
parameter_list1 = [ 0 ] * 0x12
parameter_list2 = [ 0 ] * 3
parameter_list3 = [ 0 ] * 6
#print energy_meter
error = 0
try:
index = 0
read_values1 = energy_meter.read_registers( 0 , 0x24, 4)
for i in range ( 0, 0x24, 2):
parameter_list1[index] = convert_in_float( read_values1[i], read_values1[i+1])
#print "Parameter read from register : ", hex(index), "is : ", parameter_list1[index] ,"\n"
index = index + 1
#read parameter list 2 & 3 in a similar way
error = 0
return error, parameter_list1, parameter_list2, parameter_list3, int(time.time())
except IOError or ValueError:
print "got error"
error = 1
return error, parameter_list1, parameter_list2, parameter_list3, int(time.time())
also, i have written a separate code to dump all data to server and is shown below :
import time
from pymongo import MongoClient
client = MongoClient('mongodb://10.32.36.40:27017')
db = client.clytics
collection = db['raspberry_pi']
def pushData(error, value1, value2, value3, value4):
if error == 0 :
temp_js = {
#variable assignment
}
temp_js_id = collection.insert(temp_js)
using the above two codes i have created threads for each function. and i only execute this code and after 20 minutes of execution , i get value errors and the program doesnt execute anymore. the main program is given below :
import time
from threading import Thread
from threading import Timer
from Queue import Queue
from modbus import sdm630
from dumpInDB import pushData
from processData import process_the_data
DELAY_SEC = 1
DELAY_MIN = 60
LOOP_LIMIT = 60
def getData(q):
error, parameter_list1, parameter_list2 , parameter_list3, parameter_list4= sdm630()
print "In getData - data:", parameter_list1, parameter_list2
q.put([error, parameter_list1, parameter_list2, parameter_list3, parameter_list4])
def processData(q1,q2):
sec_data = q1.get()
min_data = process_the_data(sec_data)
print "In processData - data:", sec_data, min_data
q2.put(min_data)
print "queue:", q2.qsize()
def putData(q):
#print "In putData - data:", value[0], value[1], value[2]
for i in range(0, q.qsize()):
value = q.get()
print "In putData - data:", value[0], value[1], value[2], value[3]
pushData( value[0], value[1] , value[2], value[3] , value[4])
def thread1(threadName, q):
i = 0
while 1:
t = Timer( DELAY_SEC, getData, args = (q,))
t.start()
time.sleep(DELAY_SEC)
def thread2( threadName, q1,q2):
i = 0
print "in thread2"
while 1:
t = Timer( DELAY_SEC, processData, args = (q1,q2,))
t.start()
time.sleep(DELAY_SEC)
def thread3( threadName, q):
i = 0
print "in thread3"
while 1:
t = Timer( DELAY_MIN, putData, args = (q,))
t.start()
print "schedule time - min"
time.sleep(DELAY_MIN)
queue_second = Queue()
queue_minute = Queue()
thread1 = Thread( target=thread1, args=("Thread-1", queue_second) )
thread2 = Thread( target=thread2, args=("Thread-2", queue_second, queue_minute) )
thread3 = Thread( target=thread3, args=("Thread-3", queue_minute) )
thread1.start()
thread2.start()
thread3.start()
thread1.join()
thread2.join()
thread3.join()
am stuck with this error. shown below :
minimalmodbus.Instrument<id=0xb6b2d9b8, address=2, mode=rtu, close_port_after_each_call=True, precalculate_read_size=True, debug=False, serial=Serial<id=0xb6b482f0, open=False>(port='/dev/ttyUSB0', baudrate=9600, bytesize=8, parity='N', stopbits=1, timeout=5, xonxoff=False, rtscts=False, dsrdtr=False)>
Traceback (most recent call last):
File "topScript.py", line 7, in <module>
from modbus import sdm630
File "/home/pi/scripts/modbus.py", line 60, in <module>
sdm630()
File "/home/pi/scripts/modbus.py", line 32, in sdm630
read_values1 = energy_meter.read_registers( 0 , 0x24, 4)
File "/usr/local/lib/python2.7/dist-packages/minimalmodbus.py", line 498, in read_registers
numberOfRegisters=numberOfRegisters, payloadformat='registers')
File "/usr/local/lib/python2.7/dist-packages/minimalmodbus.py", line 697, in _genericCommand
payloadFromSlave = self._performCommand(functioncode, payloadToSlave)
File "/usr/local/lib/python2.7/dist-packages/minimalmodbus.py", line 798, in _performCommand
payloadFromSlave = _extractPayload(response, self.address, self.mode, functioncode)
File "/usr/local/lib/python2.7/dist-packages/minimalmodbus.py", line 1075, in _extractPayload
raise ValueError(text)
ValueError: Checksum error in rtu mode: '\xa6\xe6' instead of '\xf7[' . The response is: '\xff\xf7HCeN\xce\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00?\x80\x00\x00?\x80\x00\x00?\x80\x00\x00\xa6\xe6' (plain response: '\xff\xf7HCeN\xce\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\
sometimes value error keeps popping up for sometime and finally fails and gives a message saying no more threads can be created.(reached to maximum level)
Your syntax to handle multiple exceptions is wrong. Use something like:
except (ValueError, IOError):
For more details see the Python tutorial https://docs.python.org/2/tutorial/errors.html
Whats the best / correct way to test a connection to a MySQL server.. can you for example ping it..? I'm using MySQLdb and python.
I want my program to be structured in the following way
....connect to MySQL server
database = MySQLdb.connect(host="127.0.0.1 etc...
While true:
**... Check to see if connection is still alive if not reconnect**
... send data to MySQL...
time.sleep(30)
This is what I have used.
import MySQLdb
try:
import MySQLdb.converters
except ImportError:
_connarg('conv')
def connect(host='ronak.local', user='my_dev_1', passwd='my_dev_1', db='my_dev1', port=3306):
try:
orig_conv = MySQLdb.converters.conversions
conv_iter = iter(orig_conv)
convert = dict(zip(conv_iter, [str,] * len(orig_conv.keys())))
print "Connecting host=%s user=%s db=%s port=%d" % (host, user, db, port)
conn = MySQLdb.connect(host, user, passwd, db, port, conv=convert)
except MySQLdb.Error, e:
print "Error connecting %d: %s" % (e.args[0], e.args[1])
return conn
def parse_data_and_description(cursor, data, rs_id):
res = []
cols = [d[0] for d in cursor.description]
for i in data:
res.append(OrderedDict(zip(cols, i)))
return res
rs_id=0;
def get_multiple_result_sets():
conn = connect()
cursor = conn.cursor( )
final_list = []
try:
conn.autocommit(True)
cursor.execute ("CALL %s%s" % (sp, args))
while True:
rs_id+=1
data = cursor.fetchall( )
listout = parse_data_and_description(cursor, data, rs_id)
print listout
if cursor.nextset( )==None:
# This means no more recordsets available
break
print "\n"
# Consolidate all the cursors in a single list
final_list.append(listout)
print final_list
except MySQLdb.Error, e:
# Lets rollback the transaction in case of an exception
conn.rollback()
print "Transaction aborted: %d: %s" % (e.args[0], e.args[1])
cursor.close( )
conn.close()
else:
# Commit the transaction in case of no failures/exceptions
conn.commit()
print "Transaction succeeded"
cursor.close( )
conn.close()