$srcdir and $datadir

[Victor Porton]

First, I've already solved my problem using setuptools and 
pkg_resources.resource_stream() and an environment variable to specify the 
path to data files.

Ben Finney wrote:
> Victor Porton <porton at narod.ru> writes:
> 
>> In GNU software written in C $srcdir and $datadir are accessible to C
>> code through generated config.h file.
> 
> For what purpose?

I want my program to work both when it is installed (using $datadir) and 
when it is not yet installed (using $srcdir).

> Given that the source may not be at that location after the program is
> compiled – especially, after the program is moved to a different machine
> – what meaning does ‘$srcdir’ have when the program is running?

In GNU system there is support of storing a value (such as source directory) 
into the program itself. If it is moved to a different machine, $srcdir 
remains the same.

> What “data directory” is specified by ‘$datadir’, and why is it assumed
> there is exactly one?

It may be exactly one, but contain subdirectories.

>> What is the right way to config directories for a Python program?
> 
> We'll need to know what those concepts mean, to be able to discuss the
> equivalent (if any) in a Python environment.

-- 
Victor Porton - http://portonvictor.org