starting new python subprocess containig module import with popen and current env giving ImportError

Question

I'm trying to start a python program as a subprocess using the following code but the subprocess outputs ImportErrors to stderr.

The code

import subprocess
import sys
import os

environment = os.environ

command = ["python", "-u", "/test/my_python_program.py"]
p = subprocess.Popen(command, stdout=subprocess.PIPE, stderr=subprocess.STDOUT, env=environment)

for line in iter(p.stdout.readline, ''):
    line = line.replace('\r', '').replace('\n', '')
    print line
    sys.stdout.flush()

The error

Traceback (most recent call last):
  File "/test/my_python_program.py", line 31, in <module>
    from PySide import QtGui, QtCore, QtNetwork
ImportError: dlopen(/Applications/Autodesk/maya2014/Maya.app/Contents/Frameworks/Python.framework/Versions/Current/lib/python2.7/site-packages/PySide/QtGui.so, 2): Library not loaded: @executable_path/libpyside-python2.7.1.1.dylib
  Referenced from: /Applications/Autodesk/maya2014/Maya.app/Contents/Frameworks/Python.framework/Versions/Current/lib/python2.7/site-packages/PySide/QtGui.so
  Reason: image not found

I'm running my code from a version of python embedded into another program (Autodesk Maya). The module's that cause the ImportError are importable from the main processes python interpreter. My assumption was that I could supply the main process's python's env to the subprocess to give it access to the modules that the main python instance had access too.

Does the approach make sense? and if so what am I doing wrong?

Edit1

I also tried to use the embedded version of python used in the popen call and the errors remained. If I remove the Import the embedded version of python runs just fine.

Edit 2

These are the environment variables that os.environ returns

MAYA_MODULE_PATH
AUTOLOADER_LAPS
LOGNAME
USER
SUBSTANCES_LOCATION
PATH
HOME
MAYA_SCRIPT_BASE
MENTALRAY_INCLUDE_LOCATION
SHELL
MAYA_LICENSE_METHOD
MAYA_LICENSE
QT_MAC_NO_NATIVE_MENUBAR
MAYA_SCRIPT_PATH
MAYA_REVERSE_FILEFORMAT_EXT
WF_IMF_CIN_WHITE_POINT
MAYA_LOCATION
PYTHONPATH
SSH_AUTH_SOCK
MENTALRAY_SHADERS_LOCATION
Apple_PubSub_Socket_Render
MAYA_PRESET_PATH
XBMLANGPATH
MAYA_RENDER_DESC_PATH
MAYA_SHADER_LIBRARY_PATH
MENTALRAY_LOCATION
TMPDIR
__KMP_REGISTERED_LIB_5123
MAYA_PLUG_IN_PATH
MAYA_APP_DIR
PYTHONHOME
MAYA_PLUG_IN_RESOURCE_PATH
__CF_USER_TEXT_ENCODING
IMF_PLUG_IN_PATH
__CHECKFIX1436934
WF_IMF_CIN_CORRECTION

Edit 3

Here's the contents of PYHOME

/Applications/Autodesk/maya2014/Maya.app/Contents/Frameworks/Python.framework/Versions/Current

Answer 1

The Python running inside Maya is not completely standard...

When run from within Maya, you might need to use the mayapy command to launch Python. This bootstraps Python according to Autodesk's requirements and should ensure the environment required to run Python is correct. (Although I think this may be what you are referring to in Edit1).

Have you also tried not passing through the environment to the popen command? I think the default behaviour of popen is to inherit the current process' environment which is what you want. I would expect the environment to be setting DYLD_LIBRARY_PATH and/or DYLD_FRAMEWORK_PATH at some point to tell it where Qt is.