Using ctypes in python to call a mojo function (mojo 0.6)

ffi.py

from ctypes import CFUNCTYPE, c_int


Ft = CFUNCTYPE(c_int, c_int, c_int)


def entry_point(ptr_to_function):
    function_pointer = Ft(ptr_to_function)
    result = function_pointer(5000, 2)
    return result

go.sh

#!/bin/sh

mojo build main.mojo
PYTHONPATH=$(pwd) ./main

main.mojo

from memory.unsafe import Pointer
from python import Python


alias Ft = fn(Int, Int) -> Int


fn fn_ptr_as_int64(f: Ft) -> Int64:
    """Recast `f` to `Int64`."""
    var fcp = f
    return Pointer[Ft].address_of(fcp).bitcast[Int64]()[0]


fn mojo_leaf(v: Int, w: Int) -> Int:
    return 2001 + v * w


def main():
    let fn_ptr = fn_ptr_as_int64(mojo_leaf)
    let ffi = Python.import_module("ffi")
    entry_point = ffi.entry_point
    print(entry_point(fn_ptr))