pundler.py

import sys
from importlib.machinery import ModuleSpec, SourceFileLoader


pundles = dict([item.strip() for item in line.split(',')] for line in open('Pundlerfile').readlines())


class PundlerFinder(object):
    def find_spec(self, fullname, path, target_module):
        if path is not None:
            return None
        if fullname not in pundles:
            return None
        version = pundles[fullname]
        path = '{module}-{version}/{module}/__init__.py'.format(module=fullname, version=version)
        return ModuleSpec(fullname, SourceFileLoader(fullname, path), origin=path)

sys.meta_path.insert(0, PundlerFinder())

import trafaret as t
print(repr(t))