diff options
Diffstat (limited to 'pkg_resources.py')
| -rw-r--r-- | pkg_resources.py | 39 |
1 files changed, 29 insertions, 10 deletions
diff --git a/pkg_resources.py b/pkg_resources.py index 4bc05e57..bde30989 100644 --- a/pkg_resources.py +++ b/pkg_resources.py @@ -504,7 +504,7 @@ class WorkingSet(object): seen[key]=1 yield self.by_key[key] - def add(self, dist, entry=None, insert=True): + def add(self, dist, entry=None, insert=True, replace=False): """Add `dist` to working set, associated with `entry` If `entry` is unspecified, it defaults to the ``.location`` of `dist`. @@ -512,8 +512,9 @@ class WorkingSet(object): set's ``.entries`` (if it wasn't already present). `dist` is only added to the working set if it's for a project that - doesn't already have a distribution in the set. If it's added, any - callbacks registered with the ``subscribe()`` method will be called. + doesn't already have a distribution in the set, unless `replace=True`. + If it's added, any callbacks registered with the ``subscribe()`` method + will be called. """ if insert: dist.insert_on(self.entries, entry) @@ -522,7 +523,7 @@ class WorkingSet(object): entry = dist.location keys = self.entry_keys.setdefault(entry,[]) keys2 = self.entry_keys.setdefault(dist.location,[]) - if dist.key in self.by_key: + if not replace and dist.key in self.by_key: return # ignore hidden distros self.by_key[dist.key] = dist @@ -532,7 +533,8 @@ class WorkingSet(object): keys2.append(dist.key) self._added_new(dist) - def resolve(self, requirements, env=None, installer=None): + def resolve(self, requirements, env=None, installer=None, + replace_conflicting=False): """List all distributions needed to (recursively) meet `requirements` `requirements` must be a sequence of ``Requirement`` objects. `env`, @@ -542,6 +544,12 @@ class WorkingSet(object): will be invoked with each requirement that cannot be met by an already-installed distribution; it should return a ``Distribution`` or ``None``. + + Unless `replace_conflicting=True`, raises a VersionConflict exception if + any requirements are found on the path that have the correct name but + the wrong version. Otherwise, if an `installer` is supplied it will be + invoked to obtain the correct version of the requirement and activate + it. """ requirements = list(requirements)[::-1] # set up the stack @@ -558,10 +566,18 @@ class WorkingSet(object): if dist is None: # Find the best distribution and add it to the map dist = self.by_key.get(req.key) - if dist is None: + if dist is None or (dist not in req and replace_conflicting): + ws = self if env is None: - env = Environment(self.entries) - dist = best[req.key] = env.best_match(req, self, installer) + if dist is None: + env = Environment(self.entries) + else: + # Use an empty environment and workingset to avoid + # any further conflicts with the conflicting + # distribution + env = Environment([]) + ws = WorkingSet([]) + dist = best[req.key] = env.best_match(req, ws, installer) if dist is None: #msg = ("The '%s' distribution was not found on this " # "system, and is required by this application.") @@ -1811,6 +1827,7 @@ def register_namespace_handler(importer_type, namespace_handler): def _handle_ns(packageName, path_item): """Ensure that named package includes a subpath of path_item (if needed)""" + importer = get_importer(path_item) if importer is None: return None @@ -1825,12 +1842,14 @@ def _handle_ns(packageName, path_item): elif not hasattr(module,'__path__'): raise TypeError("Not a package:", packageName) handler = _find_adapter(_namespace_handlers, importer) - subpath = handler(importer,path_item,packageName,module) + subpath = handler(importer, path_item, packageName, module) if subpath is not None: path = module.__path__ path.append(subpath) loader.load_module(packageName) - module.__path__ = path + for path_item in path: + if path_item not in module.__path__: + module.__path__.append(path_item) return subpath def declare_namespace(packageName): |