Issue in using "subprocess.Popen" for parsing the command output

Sun Nov 25 13:26:45 EST 2018

Thanks a lot for your quick responses Mrab and appreciate the same.
I changed the snippet as below, still it seems to be an issue,
I am using python3 version:
def main(ssid, pw):
 try:
 cmd = "nmcli device wifi connect '%s' password '%s'" % (ssid, pw)
 proc = subprocess.Popen(cmd, stdout=subprocess.PIPE,
stderr=subprocess.PIPE, shell=True, universal_newlines=True)
 stdout, stderr = proc.communicate()
 retcode = proc.returncode
 print("printing stdout!!!!!!!!!!", stdout)
 print("printing retcode!!!!!!!!!!", retcode)
 except subprocess.CalledProcessError as e:
 s = """While executing '{}' something went wrong.
 Return code == '{}'
 Return output:\n'{}'
 """.format(cmd, e.returncode, e.output, shell=True)
 raise AssertionError(s)
 #return proc.strip().decode("utf-8")
 #return proc.decode("utf-8").strip()
 #return proc.decode("utf-8")
* return stdout.strip().decode("utf-8")*
main("Apartment 18", "40672958689850014685")
/home/srinivasan/Downloads/wifidisconnectissuenov23_homework/venv/bin/python
/home/srinivasan/Downloads/wifidisconnectissuenov23_homework/qa/test_library/test4.py
printing stdout!!!!!!!!!!
printing retcode!!!!!!!!!! 0
Traceback (most recent call last):
 File
"/home/srinivasan/Downloads/wifidisconnectissuenov23_homework/qa/test_library/test4.py",
line 37, in <module>
 main("Apartment 18", "40672958689850014685")
 File
"/home/srinivasan/Downloads/wifidisconnectissuenov23_homework/qa/test_library/test4.py",
line 34, in main
 return stdout.strip().decode("utf-8")
*AttributeError: 'str' object has no attribute 'decode'*
Process finished with exit code 1
On Sun, Nov 25, 2018 at 11:49 PM MRAB <python at mrabarnett.plus.com> wrote:
> On 2018年11月25日 17:54, srinivasan wrote:
> > Hope now I have changed on the string output as below, could you
> > please correct me if am still wrong?
> >
> > import sys
> > import subprocess
> >
> > interface = "wlan0"
> >
> >
> > def main(ssid, pw):
> >
> > try:
> > cmd = "nmcli device wifi connect '%s' password '%s'" % (ssid, pw)
> >
> > proc = subprocess.Popen(cmd, stdout=subprocess.PIPE,
> > stderr=subprocess.PIPE, shell=True, universal_newlines=True)
> > stdout, stderr = proc.communicate()
> > retcode = proc.returncode
> >
> > print("printing stdout!!!!!!!!!!", stdout)
> > print("printing retcode!!!!!!!!!!", retcode)
> >
> > except subprocess.CalledProcessError as e:
> > s = """While executing '{}' something went wrong.
> > Return code == '{}'
> > Return output:\n'{}'
> > """.format(cmd, e.returncode, e.output,
> > shell=True)
> > raise AssertionError(s)
> >
> > #return proc.strip().decode("utf-8")
> > * return proc.decode("utf-8").strip()*
> >
> [snip]
>> No. As I said in _my_ post, 'proc' is the process itself. What you want
> is the string that it output, which, in your code, is 'stdout', so:
>> return stdout.strip().decode("utf-8")
>> --
> https://mail.python.org/mailman/listinfo/python-list
>