在python中完成for循环后调用子进程

Question

I have python script like below. In this script, I am collecting stdout and stderr of the script in a file and storing in Linux .

In this script, I am running the function path_finder in a loop over input_file In this script, I am using subprocess to move data in Linux to a different location.

I want this subprocess call to run after finishing the loop but instead, it runs when the loop runs for the first time and when the second time the loop runs it throws an error which is expected. As the file is present it throws an error.

#!/usr/bin/python

import os
import sys
import traceback
import subprocess

def path_finder(
    table,
    mysql_user,
    user,
    dir,
    ):


    day = datetime.now().strftime('%Y-%m-%d')
    month = datetime.now().strftime('%Y-%m')

    Linux_path = '/data/logging/{}'.format(input_file)
    New_path = '/user/{}/{}/logging/{}/{}/{}'.format(user,dir,mysql_user,month,day)

    subprocess.call(["rm", Linux_path])

    so = se = open('/data/logging/{}'.format(input_file), 'a',
                   0)

    #re-open stdout without buffering
    sys.stdout = os.fdopen(sys.stdout.fileno(), 'a', 0)

    # redirect stdout and stderr to the log file opened above
    os.dup2(so.fileno(), sys.stdout.fileno())
    os.dup2(se.fileno(), sys.stderr.fileno())

    ### CODE:

    Do something

    ### if errors the print traceback

    ### repeat the same for every table in input file

    ## Execute below statement after for loop completed

    subprocess.call(["cp", Linux_path, New_path])


if len(sys.argv) != 5:
    print 'Invalid number of args......'
    exit()

input_file = sys.argv[1]
mysql_user = sys.argv[2]
user = sys.argv[3]
dir = sys.argv[4]

input = open("{}.format(input_file)", "r")

for table in input:
    path_finder(
            table,
            mysql_user,
            user,
            dir,
            )

sc.stop()
print

How can I change my script so that the sub process call will run after the for loop is done?

Answer 1

I don't see what the problem is. The statement you want to execute last is currently present in the function 'path_finder' which is why it is running every time. To make this run only once and after the for loop is finished, put the statement after it.

for table in input:
path_finder(
        table,
        mysql_user,
        user,
        dir,
        )
subprocess.call(["cp", Linux_path, New_path])

This should do it.