def from_yaml(cls, filename):
with open(filename) as fp:
data = yaml.load(fp)
packages = collections.OrderedDict(
parse_package_list(data.get("packages", [])))
operations = data.get("request", [])
request = Request()
for operation in operations:
kind = operation["operation"]
requirement = Requirement._from_string(operation["requirement"])
getattr(request, kind)(requirement)
decisions = data.get("decisions", {})
operations = []
for operation in data.get("transaction", []):
if operation["kind"] == "install":
operations.append(InstallOperation(operation["package"]))
elif operation["kind"] == "update":
operations.append(
UpdateOperation(operation["from"], operation["to"]))
elif operation["kind"] == "remove":
operations.append(RemoveOperation(operation["package"]))
else:
msg = "invalid operation kind {!r}".format(operation["kind"])
raise ValueError(msg)
return cls(packages, [remote_repository(data, packages)],
installed_repository(data, packages), request, decisions,
operations)
# Step 2: recurse
for dependency in best_dependencies:
solution = optimize_at_level(pool, dependency, new_rules, solution)
return solution
def optimize(pool, requirement, rules):
best_package = find_best_candidate(pool, requirement, rules)
solution = [best_package]
return optimize_at_level(pool, best_package, rules, solution)
if __name__ == '__main__':
repository = repository_from_index("full_index.json")
pool = Pool([repository])
requirement_str = "scikit_learn < 0.14"
requirement = Requirement._from_string(requirement_str)
request = Request()
request.install(requirement)
rules_generator = RulesGenerator(pool, request)
rules = list(rules_generator.iter_rules())
solution = optimize(pool, requirement, rules)
for decision in solution:
print(decision.name, str(decision.version))
