python subprocess wrapper class

Deprecated in version 2.6: The commands module has been removed in Python 3.0. Use the subprocess module instead.

Try using Subprocess to say goodbye to commands.

• Prevent shell injection.
• One-liner Make your favorite mackerel tube intuitive to use.
• The image is PIPE like a filter of sqlalchemy query.

shell.py

#!/usr/bin/python

import sys
import shlex
from   subprocess import Popen, PIPE, STDOUT

__version__ = '0.0.1'

#----------------------------------------------------------
# SHELL CLASS
#----------------------------------------------------------
class Shell(object):

    def __init__(self):

        self.p  = None

    def cmd(self, cmd):

        p_args = {'stdin'     : None,
                  'stdout'    : PIPE,
                  'stderr'    : STDOUT,
                  'shell'     : False,}

        return self._execute(cmd, p_args)

    def pipe(self, cmd):

        p_args = {'stdin'     : self.p.stdout,
                  'stdout'    : PIPE,
                  'stderr'    : STDOUT,
                  'shell'     : False,}

        return self._execute(cmd, p_args)

    def _execute(self, cmd, p_args):

        try :
            self.p = Popen(shlex.split(cmd), **p_args)
            return self

        except :
            print 'Command Not Found: %s' % (cmd)
            sys.exit()

    def commit(self):

        result = self.p.communicate()[0]
        status = self.p.returncode

        return (status, result)

#----------------------------------------------------------
# TEST
#----------------------------------------------------------
def test():
    '''
    tac ./test.txt | sort | uniq -c

    '''
    shell= Shell()

    #--- CASE 1
    (return_code, stdout) = shell.cmd('tac ./test.txt').pipe('sort').pipe('uniq').commit()
    print 'RETURN_CODE: %s  \nSTDOUT: \n%s' % (return_code, stdout)

    #--- CASE 2
    s = shell.cmd('tac ./test.txt')
    s.pipe('sort')
    s.pipe('uniq')
    (return_code, stdout) = s.commit()
    print 'RETURN_CODE: %s, \nSTDOUT: \n%s' % (return_code, stdout)

if __name__ == '__main__':test()

test.txt

1
2
3
4
5
6
7
8
9
0

result

RETURN_CODE: 0
STDOUT:
0
1
2
3
4
5
6
7
8
9

RETURN_CODE: 0,
STDOUT:
0
1
2
3
4
5
6
7
8
9

Conclusion

I don't think I'm in the wrong direction, but the error handling is strange. Let's review it soon.