gensim v4.0.0.rc1 Release Notes

Release Date: 2021-03-19 // over 1 year ago
  • ⚡️ ⚠️ Gensim 4.0 contains breaking API changes! See the Migration guide to update your existing Gensim 3.x code and models.

    🚀 Gensim 4.0 is a major release with lots of performance & robustness improvements and a new website.

    Main highlights (see also 👍 Improvements below)

    a. Efficiency

    | model | 3.8.3: wall time / peak RAM / throughput | 4.0.0: wall time / peak RAM / throughput |
    | fastText | 2.9h / 4.11 GB / 822k words/s | 2.3h / **1.26 GB** / 914k words/s |
    | word2vec | 1.7h / 0.36 GB / 1685k words/s | **1.2h** / 0.33 GB / 1762k words/s |
    In other words, fastText now needs 3x less RAM (and is faster); word2vec has 2x faster init (and needs less RAM, and is faster); detecting collocation phrases is 2x faster. ([4.0 benchmarks](

    b. Robustness. We fixed a bunch of long-standing bugs by refactoring the internal code structure (see 🔴 Bug fixes below)

    c. Simplified OOP model for easier model exports and integration with TensorFlow, PyTorch &co.

    These improvements come to you transparently aka "for free", but see Migration guide for some changes that break the old Gensim 3.x API. Update your code accordingly.

    • ⬇️ Dropped a bunch of externally contributed modules: summarization, pivoted TFIDF normalization, FIXME.

      • Code quality was not up to our standards. Also there was no one to maintain them, answer user questions, support these modules.

      So rather than let them rot, we took the hard decision of removing these contributed modules from Gensim. If anyone's interested in maintaining them please fork into your own repo, they can live happily outside of Gensim.

    • ⬇️ Dropped Python 2. Gensim 4.0 is Py3.6+. Read our Python version support policy.

      • If you still need Python 2 for some reason, stay at Gensim 3.8.3.
    • A new Gensim website – finally! 🙃

    So, a major clean-up release overall. We're happy with this tighter, leaner and faster Gensim.

    ✅ This is the direction we'll keep going forward: less kitchen-sink of "latest academic algorithms", more focus on robust engineering, targetting common concrete NLP & document similarity use-cases.

    :star2: New Features

    🛠 :red_circle: Bug fixes

    • 0️⃣ fix RuntimeError in export_phrases (change defaultdict to dict) (thalishsajeed, #3041)

    :books: Tutorial and doc improvements

    • fix various documentation warnings (mpenkov, #3077)
    • Fix broken link in run_doc how-to (sezanzeb, #2991)
    • Point WordEmbeddingSimilarityIndex documentation to gensim.similarities (Witiko, #3003)
    • Make the link to the Gensim 3.8.3 documentation dynamic (Witiko, #2996)

    🚚 :warning: Removed functionality

    🔮 Miscellaneous