usage of try except for review.

[Ganesh Pal]

Iam on python 2.6 and Linux , need your suggestion on the usage of try
and except in this program and


Modified code:


#!/usr/bin/env python


"""

"""

import os

import shlex

import subprocess

import sys

import time

import logging

import run

import pdb



def run_cmd_and_verify(cmd, timeout=1000):

    try:

        out, err, ret = run(cmd, timeout=timeout)

        assert ret ==0,"ERROR (ret %d): " \

                " \nout: %s\nerr: %s\n" % (ret, out, err)

    except Exception as e:

        logging.error("Failed to run %s got %s" % (cmd, e))

        return False

    return True



def run_test():

    """

    Mount

    """

    pdb.set_trace()

    for cmd in ["mount /nfs_mount1", "mount /cifs_mount1"]:

        try:

            if not run_cmd_and_verify(cmd, timeout=3600):

                return False

        except:

           logging.error("Failure while running command %")

    logging.info("Setup and Creation ....Done !!!")



    #

    cmd = "run_scan"

    out, err, ret = run(cmd)



    for cmd in ["create_data.py -nfs ",

                "validate.py -30 "]:

        try:

            if not run_cmd_and_verify(cmd, timeout=3600):

               return False

        except:

            logging.error("")

            return False

    logging.info("Mount IS START.....Done !!!")



def main():

    if not run_test():

        sys.exit("Exiting Main")



if __name__ == '__main__':

    main()



Question 1:



1. Have I used try and expect block correctly  ? , In my case I have
the except block that's  is not needed it just gives an  message I
have still included for the sake of try block


    try:

        if not run_cmd_and_verify(cmd, timeout=3600):

                return False

    except:

           logging.error("inside except")

        return False




2.  If a failure’s are encountered  the error by assert condition the
errors are now displayed on the screen , how do I redirect it to log
file using logging error


def run_cmd_and_verify(cmd, timeout=1000):

    try:

        out, err, ret = run(cmd, timeout=timeout)

        assert ret ==0,"ERROR (ret %d): " \

                " \nout: %s\nerr: %s\n" % (ret, out, err)

    except Exception as e:

        logging.error("Failed to run %s got %s" % (cmd, e))

        return False

    return True



#script_10.py

Failed to run  mount /nfs got ERROR (ret 1):

out:
host-44-3 exited with status 1

err:
host-44-3: mount_efs:  on /nfs: efs is already mounted



3. my function def has 1000 but Iam using 3600 in the calling fnx etc
, Time out value are overwritten ?

4. Any further improvement particularly on try -except ?


Regards,
Ganesh