Alt-profanity-check
Alt profanity check is a drop-in replacement of the profanity-check library for the not so well
maintained https://github.com/vzhou842/profanity-check:
A fast, robust Python library to check for profanity or offensive language in strings. Read more about how and why
profanity-checkwas built in this blog post.
Our aim is to follow scikit-learn's (main dependency) versions and post models trained with the same version number, example alt-profanity-check version 1.2.3.4 should be trained with the 1.2.3.4 version of the scikit-learn library.
For joblib which is the next major dependency we will be using the latest one which was available when we trained the models.
Last but not least we aim to clean up the codebase a bit and maybe introduce some features or datasets.
| Learn Python from the Maintainer of alt-profanity-check 🎓🧑💻️⌨️ |
|---|
| I am teaching Python through Mentorcruise, aiming both to beginners and seasoned developers who want to get to the next level in their learning journey: https://mentorcruise.com/mentor/dimitriosmistriotis/. Please mention that you found me through this repository. |
Changelog
See CHANGELOG.md
How It Works
profanity-check uses a linear SVM model trained on 200k human-labeled samples of clean and
profane text strings. Its model is simple but surprisingly effective, meaning
profanity-check is both robust and extremely performant.
Why Use profanity-check?
No Explicit Blacklist
Many profanity detection libraries use a hard-coded list of bad words to detect and filter profanity. For example, profanity uses this wordlist, and even better-profanity still uses a wordlist. There are obviously glaring issues with this approach, and, while they might be performant, these libraries are not accurate at all.
A simple example for which profanity-check is better is the phrase
- "You cocksucker"* -
profanitythinks this is clean because it doesn't have - "cocksucker"* in its wordlist.
Performance
Other libraries like profanity-filter use more sophisticated methods that are much more accurate but at the cost of performance. A benchmark (performed December 2018 on a new 2018 Macbook Pro) using a Kaggle dataset of Wikipedia comments yielded roughly the following results:
| Package | 1 Prediction (ms) | 10 Predictions (ms) | 100 Predictions (ms) |
|---|---|---|---|
| profanity-check | 0.2 | 0.5 | 3.5 |
| profanity-filter | 60 | 1200 | 13000 |
| profanity | 0.3 | 1.2 | 24 |
profanity-check is anywhere from 300 - 4000 times faster than profanity-filter in this
benchmark!
Accuracy
This table speaks for itself:
| Package | Test Accuracy | Balanced Test Accuracy | Precision | Recall | F1 Score |
|---|---|---|---|---|---|
| profanity-check | 95.0% | 93.0% | 86.1% | 89.6% | 0.88 |
| profanity-filter | 91.8% | 83.6% | 85.4% | 70.2% | 0.77 |
| profanity | 85.6% | 65.1% | 91.7% | 30.8% | 0.46 |
See the How section below for more details on the dataset used for these results.
Installation
pip install alt-profanity-check
Python 3.10
Scikit Learn 1.8 requires Python >= 3.11, last version supporting Python 3.10 is 1.7.2.
Python 3.9
Scikit Learn supports Python >= 3.10, we had a reference for earlier versions, this makes last supported one 1.6.1.
Python 3.8
Seems that for some reason 1.4.* branches worked with Python 3.8 with that in mind last Python 3.8 version of this libreary supported is 1.4.2.
Python 3.7
From 1.1.2 and later, Python 3.7 is not supported, hence if you are using 3.6 pin alt-profanity-check to 1.0.2.1.
Python 3.6
Following Scikit-learn, Python3.6 is not supported after its 1.0 version if you are using 3.6 pin alt-profanity-check to 0.24.2.
Older Python Versions
Reference: https://scikit-learn.org/stable/install.html
Scikit-learn 0.20 was the last version to support Python 2.7 and Python 3.4. Scikit-learn 0.21 supported Python 3.5-3.7. Scikit-learn 0.22 supported Python 3.5-3.8. Scikit-learn 0.23-0.24 required Python 3.6 or newer. Scikit-learn 1.0 supported Python 3.7-3.10. Scikit-learn 1.1, 1.2 and 1.3 support Python 3.8-3.12 Scikit-learn 1.4 requires Python 3.9 or newer.
Usage
You can test from the command line:
profanity_check "Check something" "Check something else"
from profanity_check import predict, predict_prob
predict(['predict() takes an array and returns a 1 for each string if it is offensive, else 0.'])
# [0]
predict(['fuck you'])
# [1]
predict_prob(['predict_prob() takes an array and returns the probability each string is offensive'])
# [0.08686173]
predict_prob(['go to hell, you scum'])
# [0.7618861]
Note that both predict() and predict_prob return numpy
arrays.
More on How/Why It Works
How
Special thanks to the authors of the datasets used in this project. profanity-check hence also
alt-profanity-check is trained on a combined dataset from 2 sources:
- t-davidson/hate-speech-and-offensive-language, used in their paper Automated Hate Speech Detection and the Problem of Offensive Language
- the Toxic Comment Classification Challenge on Kaggle.
profanity-check relies heavily on the excellent scikit-learn
library. It's mostly powered by scikit-learn classes
CountVectorizer,
LinearSVC, and
CalibratedClassifierCV.
It uses a Bag-of-words model
to vectorize input strings before feeding them to a linear classifier.
Why
One simplified way you could think about why profanity-check works is this:
during the training process, the model learns which words are "bad" and how "bad" they are
because those words will appear more often in offensive texts. Thus, it's as if the training
process is picking out the "bad" words out of all possible words and using those to make future
predictions. This is better than just relying on arbitrary word blacklists chosen by humans!
Caveats
This library is far from perfect. For example, it has a hard time picking up on less common variants of swear words like "f4ck you" or "you b1tch" because they don't appear often enough in the training corpus. Never treat any prediction from this library as unquestionable truth, because it does and will make mistakes. Instead, use this library as a heuristic.
Developer Notes
- Create a virtual environment from the project
pip install -r development_requirements.txt
Retraining data
With the above in place:
cd profanity_check/data
python train_model.py
Test
python -m pytest --import-mode=append tests/
Uploading to PyPi
At this iteration, using Trusted Publishers, see: .github/workflows/package_release.yml.
- Go to "Releases"
- Click "Draft a new release"
- On the "Choose a tag" dropdown, create a tag for the current release version, which is following the scikit-learn tag
- Title the release as "Version va.b.c" with
a.b.cbeing the tag from the previous step - Also click "Generate release notes" to have the delta from the previous release documented
- Finally, "Publish release" from the bottom of the page
Metadata
Release files for alt-profanity-check 1.9.1
For a detailed explanation of source distributions (sdists) and built distributions (wheels), please see the package formats documentation.
Source distribution (sdist)
| File | Size | Uploaded | |
|---|---|---|---|
| alt_profanity_check-1.9.1.tar.gz | 759.3 kB | Details |
Built distribution (wheel)
| File | Interpreter | ABI | Platform | Reset |
|---|---|---|---|---|
| alt_profanity_check-1.9.1-py3-none-any.whl | Python 3 | none | any | Details |
Total release size: 1.5 MB
Release files / alt_profanity_check-1.9.1.tar.gz
| Download URL | alt_profanity_check-1.9.1.tar.gz |
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| Uploaded via |
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Provenance
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PyPI Publish Attestation
PyPI verified that this artifact, at this checksum, originated from the publisher listed below.
Signed by GitHub Actions, verified by PyPI on Sep 14, 2026.
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