Popen can't find batch file available on command line

Question

I'm trying to execute a program which is available to my command prompt but isn't in Python.

Command prompt:

C:\Users\Documents\libexe\tfc\bin\Debug>asc-dir
asc-dir.: directory not linked to an ASC directory //Expected output

Test Script:

proc = subprocess.Popen('asc-dir', stdout=subprocess.PIPE)
(result, err) = proc.communicate()

print(result)   

Error:

Traceback (most recent call last):
  File "C:\Program Files (x86)\Microsoft Visual Studio 12.0\Common7\IDE\Extensio
ns\Microsoft\Python Tools for Visual Studio\2.1\visualstudio_py_util.py", line 1
06, in exec_file
    exec_code(code, file, global_variables)
  File "C:\Program Files (x86)\Microsoft Visual Studio 12.0\Common7\IDE\Extensio
ns\Microsoft\Python Tools for Visual Studio\2.1\visualstudio_py_util.py", line 8
2, in exec_code
    exec(code_obj, global_variables)
  File "C:\Users\mryan.\git\web\PBNBApi\pbnb_cli\test.py", lin
e 9, in <module>
    proc = subprocess.Popen('asc-dir', stdout=subprocess.PIPE)
  File "C:\Python27\lib\subprocess.py", line 709, in __init__
    errread, errwrite)
  File "C:\Python27\lib\subprocess.py", line 957, in _execute_child
    startupinfo)
WindowsError: [Error 2] The system cannot find the file specified
Press any key to continue . . .

Answer 1

Looks like I needed to set shell=True

proc = subprocess.Popen('asc-dir', stdout=subprocess.PIPE, shell=True)
(result, err) = proc.communicate()