[Python-Dev] draft PEP: virtual environments

["Martin v. Löwis"]

> Not a zip file specifically - just a binary stream which organises scripts to be
> installed. If each class in a hierarchy has access to a binary stream, then
> subclasses have access to the streams for base classes as well as their own
> stream, and can install selectively from base class streams and their own stream.
> 
> class Base:
>     scripts = ... # zip stream containing scripts A, B
> 
>     def install_scripts(self, stream):
>         # ...
> 
>     def setup_scripts(self):
>         self.install_scripts(self.scripts)
> 
> class Derived:
>     scripts = ... # zip stream containing modified script B, new script C
> 
>     def setup_scripts(self):
>         self.install_scripts(Base.scripts) # adds A, B
>         self.install_scripts(self.scripts) # adds C, overwrites B

I'm not sure how many scripts you are talking about, and how long they
are. Assuming there are free, and assuming they are short, I'd not make
them separate source files again, but put them into string literals instead:

scripts = {
  'start':'''\
#!/bin/sh
echo start
''',
  'stop':'''\
#!/bin/sh
echo stop
'''
}}}

Then, your install_scripts would take a dictionary filename:script
contents. That's just as easily extensible.

Regards,
Martin