panthera

Hic sunt leones

Latin phrase reported on many maps indicating Terra incognita, unexplored or harsh land.

What

Dataframes in Clojure. Through pandas. On Python.

Disclaimer

This is very alpha, things will change fast, will break and the API is neither complete, nor settled. Since a few people have started playing with this there's a Clojars project available. Please give feedback if you're using this, every kind of contribution is appreciated (for more info check the Contributing section). At the moment everything is mostly undocumented and untested, I'm currently adding them.

Get started

Panthera uses the great libpython-clj as a backend to access Python and get pandas and numpy functionality.

To get started you need python, pandas and numpy (the latter comes with the former) on your path. Usually a:

apt-get install libpython3.6-dev
pip3 install numpy pandas xlrd # the latter is for Excel files, if you don't care you can do without

After this you can start playing around with panthera

(require '[panthera.panthera :as pt])

(-> (pt/read-csv "mycsv.csv")
    (pt/subset-cols "Col1" "Col2" "Col3")
    pt/median)

The above chain will read your csv file as a DataFrame, select only the given columns and then return a Series with the median of each column.

panthera.panthera is the home of the main API, and you can find everything there. The advice is to never :use or :refer :all the namespace because there are some functions named as core Clojure functions such as mod which in this case does the same thing as the core one, but in this case it is vectorized and it works only if the first argument is a Python object.

All of the main numpy is wrapped and accessible through a single interface from panthera.numpy.

(require '[panthera.numpy :refer [npy]])

(npy :power {:args [[1 2 3] 3]})
;=> [1 8 27]

(npy :power)
; This arity returns the actual numpy object that can be passed around to other functions as an argument

For every function there is a key, to check everything that is available just call the zero-arity version - (npy) - and you'll get a list of keys. To see how they work either check the official docs online or call (npy :your-key {:doc true}) to check the original Python docstring.

This is because while panthera.panthera is carefully wrapped method by method, but it's so large that at the moment just 35%-40% of its functionality is covered, I wanted all of numpy available, so the wrapper is fully automatically generated.

Numpy submodules (like random and linalg) will follow soon.

Contributing

Please let me know about any issues, quirks, ideas or even just to say that you're doing something cool with this! I accept issues, PRs or direct messages (you can find me also on https://clojurians.slack.com and on https://clojurians.zulipchat.com).

License

Copyright © 2019 Alan Marazzi

This program and the accompanying materials are made available under the terms of the Eclipse Public License 2.0 which is available at http://www.eclipse.org/legal/epl-2.0.