package py

py — OCaml interface to Python

%%VERSION%%

py is a ctypes interface to Python 3 for OCaml

py is distributed under the ISC license.

Homepage: https://github.com/zshipko/ocaml-py

Installation

py can be installed with opam:

opam install py

If you don't use opam consult the opam file for build instructions.

Introduction

Simple conversion from OCaml to Python:

open Py
let s = !$(String "a string")
let f = !$(Float 12.3)
let i = !$(Int 123)

See src/py.mli for a full list of types.

Call a function defined in a module and return the result:

let np = PyModule.import "numpy" in
let np_array = np $. (String "array") in
let arr = np_array $ [List [Int 1; Int 2; Int 3]] in
...

Which is shorthand for

let np = PyModule.import "numpy" in
let np_array = Object.get_attr_s np "array" in
let arr = run np_array [List [Int 1; Int 2; Int 3]] in
...

Evaluate a string and return the result:

let arr = eval "[1, 2, 3]" in
...

Get object index:

let a = arr $| Int 0 in
let b = arr $| Int 1 in
let c = arr $| Int 2 in
...

Set object index:

let _ = (a_list, Int 0) <-$| Int 123 in
let _ = (a_dict, String "key") <-$| String "value" in
...

Execute a string and return true/false depending on the status returned by Python:

if exec "import tensorflow" then
    let tf = PyModule.get "tensorflow" in  (* Load an existing module *)
    ...

Sample programs

If you installed py with opam sample programs are located in the directory opam var py:doc.

In the distribution sample programs and tests are located in the test directory. They can be built and run with:

topkg build --tests true && topkg test