Equivalent of Bash Backticks in Python [duplicate]

Answer 1

I'm using

(6:0)$ python --version Python 2.7.1

One of the examples above is:

import subprocess
proc = subprocess.Popen(["cat", "/tmp/baz"], stdout=subprocess.PIPE, shell=True)
(out, err) = proc.communicate()
print "program output:", out

For me, this failed to access the directory /tmp. After looking at the doc string for subprocess I replaced

[ "prog", "arg"]

with

"prog arg"

and got the shell expansion behavior that was desired (a la Perl's `prog arg`)

print subprocess.Popen("ls -ld /tmp/v*", stdout=subprocess.PIPE, shell=True).communicate()[0]

---

I quit using python a while back because I was annoyed with the difficulty of of doing the equivalent of perl `cmd ...`. I'm glad to find Python has made this reasonable.

Answer 2

foo = subprocess.check_output(["cat", "/tmp/baz"])

Answer 3

Easiest way is to use commands package.

import commands

commands.getoutput("whoami")

Output:

'bganesan'

Answer 4

This will not work in python3, but in python2 you can extend str with a custom __repr__ method that calls your shell command and returns it like so:

#!/usr/bin/env python

import os

class Command(str):
    """Call system commands"""

    def __repr__(cmd):
        return os.popen(cmd).read()

Which you can use like

#!/usr/bin/env python
from command import Command

who_i_am = `Command('whoami')`

# Or predeclare your shell command strings
whoami = Command('whoami')
who_i_am = `whoami`

Answer 5

output = os.popen('cat /tmp/baz').read()

Answer 6

import os
foo = os.popen('cat /tmp/baz', 'r').read()