Pythonx

Python Interpreter in Elixir

Proof of Concept

Low-Level

iex> alias Pythonx.C
iex> alias Pythonx.C.PyDict
iex> alias Pythonx.C.PyLong
iex> alias Pythonx.C.PyRun
iex> alias Pythonx.C.PyUnicode
iex> Pythonx.initialize_once()
iex> globals = PyDict.new()
#Reference<0.1798353731.1418330114.239105>
iex> locals = PyDict.new()
#Reference<0.1798353731.1418330114.239123>
iex> a = PyLong.from_long(1)
#Reference<0.1798353731.1418330114.239141>
iex> b = PyLong.from_long(2)
#Reference<0.1798353731.1418330114.239155>
iex> PyDict.set_item_string(locals, "a", a)
true
iex> PyDict.set_item_string(locals, "b", b)
true
iex> PyRun.string("c = a + b", C.py_file_input(), globals, locals)
#Reference<0.1798353731.1418330117.241204>
iex> c = PyUnicode.from_string("c")
#Reference<0.1798353731.1418330117.241222>
iex> val_c = PyDict.get_item_with_error(locals, c)
#Reference<0.1798353731.1418330117.241236>
iex> PyLong.as_long(val_c)
3

Very High Level

Python Code Evaluation

defmodule MyModule do
  import Pythonx

  def do_stuff_in_python do
    pyeval(
      """
      import math
      x = 5
      y = 6
      z = (x, y)
      x = math.pow(x, 2)
      """,
      return: [:x, :y, :z] # <- list of variables to return to Elixir
    )
    
    # these variables will be automatically defined in the current scope
    # {25, 6, {5, 6}} == {x, y, z}
  end
end

Executes a command with the embedded python3 executable

iex> import Pythonx
iex> python3! "path/to/script.py"
iex> python3! ["path/to/script.py", "arg1", "arg2"]

Executes a command with the embedded pip module

iex> import Pythonx
iex> pip! ["install", "-U", "numpy"]
iex> pip! ["install", "-U", "yt-dlp"]

Use an external python library

iex> import Pythonx
iex> video_id = "dQw4w9WgXcQ"
iex> pyeval(
...>   """
...>   from yt_dlp import YoutubeDL
...>   import json
...>   with YoutubeDL(params={'quite': True}) as ytb_dl:
...>   info = ytb_dl.extract_info('https://www.youtube.com/watch?v=#{video_id}', download=False)
...>   info = json.dumps(info, indent=2)
...>   """,
...>   return: [:info]
...> )
[youtube] Extracting URL: https://www.youtube.com/watch?v=dQw4w9WgXcQ
[youtube] dQw4w9WgXcQ: Downloading webpage
[youtube] dQw4w9WgXcQ: Downloading ios player API JSON
[youtube] dQw4w9WgXcQ: Downloading player a95aa57a
[youtube] dQw4w9WgXcQ: Downloading m3u8 information
iex> IO.puts(info)

Installation

If available in Hex, the package can be installed by adding pythonx to your list of dependencies in mix.exs:

def deps do
  [
    {:pythonx, "~> 0.1.0"}
  ]
end

Documentation can be generated with ExDoc and published on HexDocs. Once published, the docs can be found at https://hexdocs.pm/pythonx.