Follow the given steps to implement this recipe:

1. Create a file named lib.rs and open it your text editor.
2. Write the code header with the relevant information:

        //-- #########################
        //-- Task: Rust Function for python
        //-- Author: Vigneshwer.D
        //-- Version: 1.0.0
        //-- Date: 14 April 17
        //-- #########################

3. Create the double_input function in the Rust script with the given attributes:

        #[no_mangle]
        pub extern fn double_input(input: i32) -> i32 {
          input * 2
        }

4. Create the main.py file, which is the Python code:

        from ctypes import cdll
        from sys import platform
        if platform == 'darwin':
            prefix = 'lib'
            ext = 'dylib'
        elif platform == 'win32':
            prefix = ''
            ext = 'dll'
        else:
            prefix = 'lib'
            ext = 'so'
        lib = cdll.LoadLibrary('target/debug/{}double_input
        .{}'.format(prefix, ext))
        double_input = lib.double_input
        input = 4
        output = double_input(input)
        print('{} * 2 = {}'.format(input, output))

5. Create Makefile for creating the build rules:

        ifeq ($(shell uname),Darwin)
        EXT := dylib
        else
        EXT := so
        endif

        all: target/debug/libdouble_input.$(EXT)
        python src/main.py

        target/debug/libdouble_input.$(EXT): src/lib.rs
        Cargo.toml
        cargo build

        clean:
        rm -rf target

We will get the following output on the successful execution of our code: