Cardinality Estimation Python Packages

hyperloglog

Hyper LogLog (native and sliding) cardinality counters

hll

Fast HyperLogLog for Python.

estndv

Learned model to estimate number of distinct values (NDV) of a population using a small sample.

outrank

A Python library for efficient feature ranking and selection on sparse data sets.

cardinalitykit

A comprehensive Python toolkit for cardinality estimation algorithms (Flajolet-Martin, LogLog, SuperLogLog, HyperLogLog, HyperReal) — enabling privacy-preserving analytics, audience measurement, and sample-to-population extrapolation through probabilistic counting techniques.

samkhya

Engine-agnostic Rust SDK for portable, feedback-driven cardinality correction in embedded analytical engines: DataFusion, DuckDB, Polars, Postgres, Iceberg, Arrow, GPU, Python. One Corrector trait — GBT, TabPFN-2.5, LLM. LpJoinBound never-regress clamp. Apache-2.0.

affirmative-sampling

Reference implementation of the Affirmative Sampling algorithm by Jérémie Lumbroso and Conrado Martínez (2022). 🍀