Call Python code from an existing project written in Swift
In Swift 4.2 there was an approved feature to allow dynamic languages to be ported directly into swift
https://github.com/apple/swift-evolution/blob/master/proposals/0195-dynamic-member-lookup.md
Will look similar to:
// import pickle
let pickle = Python.import("pickle")
// file = open(filename)
let file = Python.open(filename)
// blob = file.read()
let blob = file.read()
// result = pickle.loads(blob)
let result = pickle.loads(blob)
I found this excellent and up to date gist that walks you through a complete solution: https://github.com/ndevenish/Site-ndevenish/blob/master/_posts/2017-04-11-using-python-with-swift-3.markdown
If you can get away with just using NSTask to launch a Python process, that's a pretty good option too.
In swift 5 you can try PythonKit framework.
Here's example of the usage:
import PythonKit
let sys = try Python.import("sys")
print("Python \(sys.version_info.major).\(sys.version_info.minor)")
print("Python Version: \(sys.version)")
print("Python Encoding: \(sys.getdefaultencoding().upper())")