I really want to get this right because I keep running into it when generating some big py2app/py2exe packages. I have my package that contains a lot of modules/packages that might also be in the users site packages/default location (if a user has a python distribution) but I want my distributed packages to take effect before them when running from my distribution.
Now from what I've read here
PYTHONPATH should be the first thing added to
sys.path after the current directory, however from what I've tested on my machine that is not the case and all the folders defined in
$site-packages$/easy-install.pth take precedence over this.
Could someone please give me some more in-depth explanation about this import order and help me find a way to set the environmental variables in such a way that the packages I distribute take precedence over the default installed ones?
So far my attempt is, for example on Mac-OS py2app, in my entry point script:
os.environ['PYTHONPATH'] = DATA_PATH + ':' os.environ['PYTHONPATH'] = os.environ['PYTHONPATH'] + os.path.join(DATA_PATH , 'lib') + ':' os.environ['PYTHONPATH'] = os.environ['PYTHONPATH'] + os.path.join( DATA_PATH, 'lib', 'python2.7', 'site-packages') + ':' os.environ['PYTHONPATH'] = os.environ['PYTHONPATH'] + os.path.join( DATA_PATH, 'lib', 'python2.7', 'site-packages.zip')
This is basically the structure of the package generated by py2app. Then I just:
SERVER = subprocess.Popen([PYTHON_EXE_PATH, '-m', 'bin.rpserver' , cfg.RPC_SERVER_IP, cfg.RPC_SERVER_PORT], shell=False, stdin=IN_FILE, stdout=OUT_FILE, stderr=ERR_FILE)
PYTHON_EXE_PATH is the path to the python executable that is added by py2app to the package. This works fine on a machine that doesn't have a python installed. However, when python distribution is already present, its site-packages take precedence.