The answer

[Jive Dadson]

Okay, with your help I've figured it out. Instructions are below, but
read the caveat by Ben Fenny in this thread. All this stuff is good for
one default version of Python only. The PYTHONPATH described below, for
example, cannot specify a version number. Yes, that's a pain in the
butt, but there's no way around it. If you switch versions, you may
have to delete all the .pyc files that will show up in the module
folders. Python ought to check them to see if they are valid, but I do
not know if it does so.

These instructions are for MS Windows.

1) Create your modules folder. Let's say it's named "Modules." The
documentation calls it a "package."

2) In an explorer window or on the desktop, right click on My Computer,
and select Properties.

3) Select the Advanced tab, and click on Environment Variables near the
bottom.

4) Look for an environment variable named PYTHONPATH.

a) If you do not find one, create one using the New button(s). I
don't know if it has to be in User Variables or System Variables. To
save time experimenting, I just put one in both. For the value, put the
full path of the folder Modules.

b) If there's already a PYTHONPATH, Edit it, adding a semi-colon
and the full path of folder Module to the end.

5) Put your module folders into the folder Module.

6) (Here's a really arcane bit.) Into each module folder, put a file
named __init__.py. It will be executed when you load the module. It
can be empty, but it has to be there or else the module folder will be
ignored.

 

[alex23]

These instructions are for MS Windows.

1) Create your modules folder. Let's say it's named "Modules."  The
documentation calls it a "package."

2) In an explorer window or on the desktop, right click on My Computer,
and select Properties.

3) Select the Advanced tab, and click on Environment Variables near the
bottom.

4) Look for an environment variable named PYTHONPATH.

    a) If you do not find one, create one using the New button(s). I
don't know if it has to be in User Variables or System Variables.  To
save time experimenting, I just put one in both. For the value, put the
full path of the folder Modules.

    b) If there's already a PYTHONPATH,  Edit it, adding a semi-colon
and the full path of folder Module to the end.

5) Put your module folders into the folder Module.

6) (Here's a really arcane bit.) Into each module folder, put a file
named __init__.py.  It will be executed when you load the module.  It
can be empty, but it has to be there or else the module folder will be
ignored.

Actually, if you're using Python 2.6+/3.x, you can effectively skip
steps 1-5, as these versions now support user site-packages.

Rather than create a Module folder and modify your PYTHONPATH, add (if
it doesn't exist already) the following folder:
%APPDATA%/Python/Python26/site-packages

Modules can sit directly in the folder, or within packages.

For more details: http://www.python.org/dev/peps/pep-0370/

 

[Lie Ryan]

Okay, with your help I've figured it out. Instructions are below, but
read the caveat by Ben Fenny in this thread. All this stuff is good for
one default version of Python only. The PYTHONPATH described below, for
example, cannot specify a version number. Yes, that's a pain in the
butt, but there's no way around it. If you switch versions, you may
have to delete all the .pyc files that will show up in the module
folders. Python ought to check them to see if they are valid, but I do
not know if it does so.

Err... "The answer" to... what?

 

[samwyse]

Okay, with your help I've figured it out.  Instructions are below, but
read the caveat by Ben Fenny in this thread.  All this stuff is good for
one default version of Python only.  The PYTHONPATH described below, for
example, cannot specify a version number.  Yes, that's a pain in the
butt, but there's no way around it.  If you switch versions, you may
have to delete all the .pyc files that will show up in the module
folders.  Python ought to check them to see if they are valid, but I do
not know if it does so.

These instructions are for MS Windows.

1) Create your modules folder. Let's say it's named "Modules."  The
documentation calls it a "package."

2) In an explorer window or on the desktop, right click on My Computer,
and select Properties.

3) Select the Advanced tab, and click on Environment Variables near the
bottom.

4) Look for an environment variable named PYTHONPATH.

    a) If you do not find one, create one using the New button(s). I
don't know if it has to be in User Variables or System Variables.  To
save time experimenting, I just put one in both. For the value, put the
full path of the folder Modules.

    b) If there's already a PYTHONPATH,  Edit it, adding a semi-colon
and the full path of folder Module to the end.

5) Put your module folders into the folder Module.

6) (Here's a really arcane bit.) Into each module folder, put a file
named __init__.py.  It will be executed when you load the module.  It
can be empty, but it has to be there or else the module folder will be
ignored.

In your original thread, you never quite said why you can't use site-
packages and .pth files. Are you not allowed to modify your local
installation? If you are writing something for distribution to
others, then site-packages and .pth files are the best way to go,
since they don't assume any particular operating system. If you can't
(or won't) use them, then just create Module as a sub-directory of
wherever your program lives, since that directory is always prepended
to PYTHONPATH. If you need to use the same module from multiple
directories, most modern operating systems support symbolic links; if
you're using Windows, well, here's a nickel kid, get yourself a better
computer (http://farm1.static.flickr.com/
89/240711122_f9888e5a3b_o.jpg).

I don't think that __init__.py is very arcane, since it is described
in detail in the documentation. It's also a great place to use the
standard site.addsitedir() function, which is another platform
independent way to manipulate Python's search path.