SwiftPython – The easiest way to integrate Python into iOS applications

SwiftPython makes it easy to integrate Python into iOS applications, simply by including this Swift package as a dependency. The package enables Swift apps to start an embedded Python interpreter, execute Python functions and custom scripts, and receive their output directly in Swift.

Features:

1. Includes a pre-built Python library that embeds a Python interpreter directly into iOS applications.
2. Built-in support for popular Python packages, including NumPy and pandas.
3. Interaction between Swift and Python via PythonKit.
4. We provide a build script for customizing the Python library with additional packages, if required (see below).

The default version is Python 3.10.

Installation

As with any other Swift package, simply include the path to this repository as dependency in the Swift package manager:

https://github.com/RealLast/SwiftPython

Alternatively, include the package using SPM:

import PackageDescription

let package = Package(
    name: "YourProject",
    dependencies: [
        .package(url: "https://github.com/RealLast/SwiftPython", branch: "main")
    ],
    targets: [
        .target(
            name: "YourProject",
            dependencies: ["SwiftPython"])
    ]
)

Usage

You can find a demo application under DemoApp/SwiftPythonDemoApp

Create a Python File, e.g., "MyPythonModule.py":

def say_hello(text):
    string = f"PythonModule says \"{text}\""
    print(string)
    return string

Place it under Resources:

In your Swift code, you can import SwiftPython and start the Python Interpreter. Afterward you can import your module and call any functions or instantiate classes defined in the python code:

SwiftPython.startPythonInterpreter()
let myModule = Python.import("MyPythonModule")
let result = myModule.say_hello("Hello World")

You can even use the output of your Python function in a SwiftUI view:

import SwiftUI
import SwiftPython
import PythonKit
@main
struct SwiftPythonDemoAppApp: App {
    
    var pythonText = ""
    var body: some Scene {
        WindowGroup {
            ContentView()
            Text(pythonText)
        }
    }
    
    init() {
        SwiftPython.startPythonInterpreter()
        
        let myModule = Python.import("MyPythonModule")
        let result = myModule.say_hello("Hello World")
        pythonText = "\(result)"
    }
    
    func printPythonVersion() {
        let sys = Python.import("sys")
        let text = ("Python \(sys.version_info.major).\(sys.version_info.minor)")
        print("Got Python version \(text)")
    }
}

Supported python packages

The following packages are currently included by default:

• python stdlib (i.e., sys, path, os, ...)
• numpy
• pandas
• matplotlib

How can I include further Python packages?

If you want to add more python packages, you need to build the Python binary from scratch (see below). The Python binary is built using briefcase. It supports including Python packages from pypi. You can include any pip package as long as, either:

1. The package is python-only, which is true for most packages.
2. Or, the package is not python-only but is supported by briefcase, check here: supported python packages with native components.

To include further packages, check out the instructions below on how to build python binary (xcframework) from scratch:

Building the python binary from scratch (to include more packages)

1. Installing dependencies:

Install briefcase:

pip install beeware

2. Adding packages:

Open the file pyproject.toml under PythonFramework/compile/pythonframework.

Find the Line saying "Add your cross-platform app requirements here":

requires = [
    # Add your cross-platform app requirements here
    "numpy",
    "pandas",
    "matplotlib"
]

Add your required pip package. Make sure it fullfills the requirements. For example, add CLAID:

requires = [
    # Add your cross-platform app requirements here
    "numpy",
    "pandas",
    "matplotlib",
    "claid==0.6.4"
]

3. Building

Use make to build the package:

make all

4. Updating the path to the framework:

In the Package.swift of this repository, you can find the following lines which include the prebuilt xcframework which we provide:

.binaryTarget(
        name: "PythonFramework",
        url: "https://github.com/RealLast/SwiftPython/releases/download/v0.9/Python.xcframework.zip",
        checksum: "dadedc75985f60f803fa0077ed26bb15ca102de6c8628163735a83a57ef95839"
    ),

As you see, this points to our prebuilt binary hosted on GitHub. Since you just built an updated package locally, you need to change this statement to include your local xcframework:

.binaryTarget(
    name: "PythonFramework",
    path: "PythonFramework/prebuilt/Python.xcframework"
),