knarrow
Shoot a knarrow to the knee ;)
(The lib is better than this pun, I swear.)
Detect knee points in various scenarios using a plethora of methods
Usage
Just plug in your values in a list, tuple or an np.ndarray and watch knarrow hit the knee:
>>> from knarrow import find_knee
>>> find_knee([1, 2, 3, 4, 6]) # use a list
3
>>> find_knee((1, 2, 3, 4, 6)) # or a tuple
3
>>> import numpy as np
>>> y = np.array([1.0, 1.05, 1.15, 1.28, 1.30, 2.5, 3.6, 4.9])
>>> find_knee(y) # provide just the values
4
>>> x = np.arange(8)
>>> find_knee(x, y) # or both x and y
4
>>> A = np.vstack((x, y))
>>> A
array([[0. , 1. , 2. , 3. , 4. , 5. , 6. , 7. ],
[1. , 1.05, 1.15, 1.28, 1.3 , 2.5 , 3.6 , 4.9 ]])
>>> find_knee(A) # works with x in first row, y in the second
4
>>> A.T
array([[0. , 1. ],
[1. , 1.05],
[2. , 1.15],
[3. , 1.28],
[4. , 1.3 ],
[5. , 2.5 ],
[6. , 3.6 ],
[7. , 4.9 ]])
>>> find_knee(A.T) # also works with x in the first column, y in the second column
4
>>> find_knee(x, y, smoothing=0.01) # for better results use cubic spline smoothing
4
CLI
This library can also come with a handy CLI if you install it with the cli extra:
$ pip install "knarrow[cli]"
$ cat data.txt | knarrow -
<stdin> 11
$ cat data.txt | knarrow -o value -
<stdin> 59874.14171519781845532648
$ knarrow --sort -d ',' -o value shuf_delim.txt
shuf_delim.txt 20
(the - for stdin is, unfortunately, mandatory)
Try writing knarrow --help for more info.
Similar projects
While I've come up with most of these methods by myself, I am not the only one. Here is a (non-comprehensive) list of projects I've found that implement a similar functionality and may have been an inspiration for me:
Note: this project was bootstrapped by python-blueprint. Since then, it has been heavily modified, though.
1 maintainer
Metadata
1 maintainer
Release files for knarrow 0.9.1
For a detailed explanation of source distributions (sdists) and built distributions (wheels), please see the package formats documentation.
Source distribution (sdist)
| File | Size | Uploaded | |
|---|---|---|---|
| knarrow-0.9.1.tar.gz | 18.5 kB | Details |
Built distribution (wheel)
| File | Interpreter | ABI | Platform | Reset |
|---|---|---|---|---|
| knarrow-0.9.1-py3-none-any.whl | Python 3 | none | any | Details |
Total release size: 40.3 kB
Release files / knarrow-0.9.1.tar.gz
| Download URL | knarrow-0.9.1.tar.gz |
|---|---|
| Size | 18.5 kB |
| Tags | Source |
|
SHA-256 checksum How to use checksums |
ff87f9c6adc8bb08d7d9195f79875754ef1db73aedf95e1bc3bd4804d4952c9f
|
|
BLAKE2b-256 checksum How to use checksums |
7694fbe3730f88bc9344d2b2abd261f9564cd3cad10d5ba304aad974c8cfae76
|
| Upload date | |
|
Uploaded using Trusted Publishing? What is trusted publishing? |
Yes |
| Uploaded via |
twine/6.1.0 CPython/3.13.7
|
Provenance
Provenance describes where a file came from. On PyPI, provenance is shared via attestations, which provide a verifiable record of the build or publishing details. View details, limitations and caveats.
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 Apr 4, 2026.
Transparency logRelease files / knarrow-0.9.1-py3-none-any.whl
| Download URL | knarrow-0.9.1-py3-none-any.whl |
|---|---|
| Size | 21.7 kB |
| Tags | Python 3 |
|
SHA-256 checksum How to use checksums |
b98cca020567d514b005e04fe0d1708a3a2b2247bc53e5d83cb5a7234e4997b9
|
|
BLAKE2b-256 checksum How to use checksums |
5df9c08c3dd5ed493b15d851356cf1b66417dcdd23e5bb18d82718cd77e15c23
|
| Upload date | |
|
Uploaded using Trusted Publishing? What is trusted publishing? |
Yes |
| Uploaded via |
twine/6.1.0 CPython/3.13.7
|
Provenance
Provenance describes where a file came from. On PyPI, provenance is shared via attestations, which provide a verifiable record of the build or publishing details. View details, limitations and caveats.
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 Apr 4, 2026.
Transparency log
