If you want a full python interpreter, you should look at https://github.com/go-python/gpython, but gpython also doesn't have a full standard library implemented.
-- Raffaele On Mon, Dec 10, 2018 at 1:58 AM Justin Israel <justinisr...@gmail.com> wrote: > > > On Mon, Dec 10, 2018, 9:39 PM <mic...@scylladb.com> wrote: > >> >> >> On Friday, December 7, 2018 at 9:05:02 PM UTC+1, Nate Finch wrote: >>> >>> I’d like to announce starlight - >>> https://github.com/starlight-go/starlight. >>> >>> >>> Starlight wraps google’s Go implementation of the starlark python >>> dialect <https://github.com/google/starlark-go> (most notably found in >>> the Bazel build tool). Starlight makes it super easy for users to extend >>> your application by writing simple python scripts that interact seamlessly >>> with your current Go code… with no boilerplate on your part. >>> >> >> Do you think it is suitable for porting python applications? >> Usually you go through cgo like this >> https://www.datadoghq.com/blog/engineering/cgo-and-python/ it could be >> an interesting alternative. >> >> > > The documentation for Starlark says it is a subset of python, originally > targeted at being a configuration language for Bazel. So it wouldn't be > complete enough to straight port full Python applications, unless you > really backed alot of it with Go code. The cgo approach gives you full > access to the CPython API and to embed an interpreter. > > Starlight does sound interesting though for allowing specific extension > scripts for a Go application. > > >>> *Parser by google* >>> >>> The parser and runner are maintained by google’s bazel team, which write >>> starlark-go. Starlight is a wrapper on top of that, which makes it so much >>> easier to use starlark-go. The problem with the starlark-go API is that it >>> is more built to be a used as configuration, so it assumes you want to get >>> information out of starlark and into Go. It’s actually pretty difficult to >>> get Go information into a starlark script…. unless you use starlight. >>> >>> *Easy two-way interaction* >>> >>> >>> Starlight has adapters that use reflection to automatically make any Go >>> value usable in a starlark script. Passing an *http.Request into a >>> starlark script? Sure, you can do name = r.URL.Query()["name"][0] in >>> the python without any work on your part. >>> >>> Starlight is built to *just work* the way you hope it’ll work. You can >>> access any Go methods or fields, basic types get converted back and forth >>> seamlessly… and even though it uses reflection, it’s not as slow as you’d >>> think. A basic benchmark wrapping a couple values and running a starlark >>> script to work with them runs in a tiny fraction of a millisecond. >>> >>> The great thing is that the changes made by the python code are >>> reflected in your go objects, just as if it had been written in Go. So, set >>> a field on a pointer to a struct? Your go code will see the change, no >>> additional work needed. >>> >>> *100% Safe* >>> >>> >>> The great thing about starlark and starlight is that the scripts are >>> 100% safe to run. By default they have no access to other parts of your >>> project or system - they can’t write to disk or connect to the internet. >>> The only access they have to the outside is what you give them. Because of >>> this, it’s safe to run untrusted scripts (as long as you’re not giving them >>> dangerous functions to run, like os.RemoveAll). But at the same time, >>> if you’re only running trusted scripts, you can give them whatever you want >>> (http.Get? Sure, why not?) >>> >>> *Caching* >>> >>> >>> In a production environment, you probably want to only read a script >>> once and parse it once. You can do that with starlight’s Cache. This >>> cache takes a list of directories to look in for scripts, which it will >>> read and parse on-demand, and then store the parsed object in memory for >>> later use. It also uses a cache for any load() calls the scripts use to >>> load scripts they depend on. >>> >>> *Work Ongoing* >>> >>> >>> Starlight is still a work in progress, so don’t expect the API to be >>> perfectly stable quite yet. But it’s getting pretty close, and there >>> shouldn’t be any earth shattering changes, but definitely pin your imports. >>> Right now it’s more about finding corner cases where the starlight wrappers >>> don’t work quite like you’d expect, and supporting the last few things that >>> aren’t implemented yet (like channels). >>> >>> >>> *Example* >>> >>> >>> Here's a simple example of how easy it is to extend the behavior of your >>> application with a python script. Just pass starlight whatever go values >>> you want your python script to act on, and any changes the python code >>> makes get reflected in your go code. >>> >>> >>> package main >>> >>> import ( >>> "fmt" >>> "log" >>> "time" >>> >>> "github.com/starlight-go/starlight" >>> ) >>> >>> // Starlight makes it easy to get values in and out of your starlark >>> scripts. >>> // Just pass in pointers to values that you want changed, or callback >>> functions >>> // that propagate data. >>> >>> // In theory, starlight also returns all global variables set by the >>> script, but >>> // in real programs, you need well-defined outputs for your calling code >>> to act on. >>> // If I write a script that creates a variable called nate_is_awesome = >>> 1337 ... your >>> // go code probably isn't going to care that the variable exists. >>> >>> // The best way to do it is to write a "results" struct that you pass >>> in, just >>> // as you would for any other function. >>> >>> type Page struct { >>> Name string >>> Date time.Time >>> Contents string >>> IsDraft bool >>> } >>> >>> const code = ` >>> def run(): >>> if "nate" in page.Name: >>> # capitalize words >>> page.Name = page.Name.title() >>> page.Name += " " + page.Date.Format("2006/01/02") >>> page.IsDraft = False >>> run() >>> ` >>> >>> func main() { >>> p := &Page{ >>> Name: "a story about nate", >>> Date: time.Now(), >>> Contents: "I like to write go code.", >>> IsDraft: true, >>> } >>> globals := map[string]interface{}{ >>> "page": p, >>> } >>> _, err := starlight.Eval([]byte(code), globals, nil) >>> if err != nil { >>> log.Fatal(err) >>> } >>> fmt.Printf("%v is draft: %v\n", p.Name, p.IsDraft) >>> } >>> >>> // Running it: >>> // $ go run inout.go >>> // A Story About Nate 2018/12/07 is draft: false >>> >>> -- >> You received this message because you are subscribed to the Google Groups >> "golang-nuts" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to golang-nuts+unsubscr...@googlegroups.com. >> For more options, visit https://groups.google.com/d/optout. >> > -- > You received this message because you are subscribed to the Google Groups > "golang-nuts" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to golang-nuts+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. 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