async - go and python

main.go

// https://repl.it/@fswerneck/goroutines
package main

import "fmt"

func consume(q <-chan interface{}, finish chan<- bool) {
	fmt.Println("getting from q")
	mydata := <-q

	fmt.Printf("got %v from q\n", mydata)
	finish <- true
}

func main() {
	q := make(chan interface{}, 2)
	finish := make(chan bool)

	tasks := 5
	fmt.Println("q created")

	fmt.Println("scheduling 10 goroutines")
	for i := 0; i < tasks; i++ {
		go consume(q, finish)
	}

	q <- 1
	fmt.Println("put 1")
	q <- 2
	fmt.Println("put 2")
	q <- 3
	fmt.Println("put 3")
	q <- 4
	fmt.Println("put 4")
	q <- 5
	fmt.Println("put 5")

	for i := 0; i < tasks; i++ {
		<-finish
	}

	fmt.Println("finished")
}

main.py

# https://repl.it/@fswerneck/coroutines

import asyncio

async def consume(q: asyncio.Queue):
    print("getting from q")
    mydata = await q.get()

    print(f"got {mydata} from q")
    q.task_done()


async def main():
    q = asyncio.Queue(2)

    tasks = 5
    print("q created")

    print("scheduling 10 coroutines")
    for i in range(tasks):
        asyncio.ensure_future(consume(q))

    await q.put(1)
    print("put 1")
    await q.put(2)
    print("put 2")
    await q.put(3)
    print("put 3")
    await q.put(4)
    print("put 4")
    await q.put(5)
    print("put 5")

    await q.join()

    print("finished")


# The piece below is completely abstracted by Go;
# everything in Go runs in an event loop.
loop = asyncio.get_event_loop()
loop.run_until_complete(main())

outputs.md

go:

$ go run main.go 
q created
scheduling 10 goroutines
put 1
put 2
getting from q
got 1 from q
put 3
getting from q
got 2 from q
put 4
getting from q
got 3 from q
put 5
getting from q
got 4 from q
getting from q
got 5 from q
finished

python:

$ python3 main.py 
q created
scheduling 10 coroutines
put 1
put 2
getting from q
got 1 from q
getting from q
got 2 from q
getting from q
getting from q
getting from q
put 3
put 4
got 3 from q
got 4 from q
put 5
got 5 from q
finished