def get_private_reader(self, *ignore, metadata, privacy, database, **kwargs):
if database not in self.connections:
return None
else:
from snsql.sql import PrivateReader
conn = self.connections[database]
if self.engine.lower() == "spark":
if database.lower() != 'pums_large':
conn.createOrReplaceTempView("PUMS")
conn = self.session
priv = PrivateReader.from_connection(
conn,
metadata=metadata,
privacy=privacy
)
if self.engine.lower() == "spark":
priv.reader.compare.search_path = ["PUMS"]
return priv
from snsql.sql.privacy import Privacy
from snsql.sql.parse import QueryParser
git_root_dir = subprocess.check_output(
"git rev-parse --show-toplevel".split(" ")).decode("utf-8").strip()
meta_path = os.path.join(git_root_dir, os.path.join("datasets",
"PUMS_pid.yaml"))
csv_path = os.path.join(git_root_dir, os.path.join("datasets", "PUMS_pid.csv"))
meta = Metadata.from_file(meta_path)
pums = pd.read_csv(csv_path)
query = 'SELECT AVG(age), STD(age), VAR(age), SUM(age), COUNT(age) FROM PUMS.PUMS GROUP BY sex'
q = QueryParser(meta).query(query)
privacy = Privacy(alphas=[0.01, 0.05], delta=1 / (math.sqrt(100) * 100))
priv = PrivateReader.from_connection(pums, privacy=privacy, metadata=meta)
subquery, root = priv._rewrite(query)
acc = Accuracy(root, subquery, privacy)
class TestAccuracy:
def test_count_accuracy(self):
error = acc.count(alpha=0.05)
assert (error < 7.53978 and error > 0.5)
error_wide = acc.count(alpha=0.01)
assert (error_wide < 9.909)
assert (error_wide > error)
def test_count_accuracy_small_delta(self):
acc = Accuracy(root, subquery, privacy=Privacy(epsilon=1.0, delta=0.1))