这段程序我写的问题在哪呢？为什么 Python 比 Go 要慢？

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服务器端程序（ python、go 分别去请求他）

package main

import (
	"log"
	"math/rand"
	"net/http"
	"time"
)

func hello(w http.ResponseWriter, r *http.Request) {
	time.Sleep(time.Second * time.Duration(rand.Intn(5)))
	w.Write([]byte("hello world"))
}

func main() {
	http.HandleFunc("/", hello)
	if err := http.ListenAndServe(":8080", nil); err != nil {
		log.Fatal(err)
	}
}

下面是比较的程序：

python 版本：

time python main.py 输出是 python main.py 0.37s user 0.13s system 3% cpu 16.545 total

import concurrent.futures
import requests


def do_run(task_name):
    resp = requests.get("http://localhost:8080")
    return f"{task_name}-{resp.content}"


if __name__ == "__main__":
    with concurrent.futures.ThreadPoolExecutor(max_workers=5) as executor:
        futures = [executor.submit(do_run, f"task-{i}") for i in range(40)]
        for future in concurrent.futures.as_completed(futures):
            print(future.result())
        print("Done!")

go 版本：

time go run main.go 输出是： go run main.go 0.63s user 0.33s system 19% cpu 4.927 total

package main

import (
	"fmt"
	"io/ioutil"
	"log"
	"net/http"
	"sync"
)

var httpClient http.Client

func init() {
	httpClient = *http.DefaultClient
}

func doRun(taskName string, taskChan chan string, wg *sync.WaitGroup) {
	resp, err := httpClient.Get("http://localhost:8080")
	if err != nil {
		taskChan <- "error"
		log.Fatal(err)
	}
	b, err := ioutil.ReadAll(resp.Body)
	if err != nil {
		taskChan <- "error"
		log.Fatalln(err)
	}
	taskChan <- fmt.Sprintf("%s--%s", taskName, string(b))
	wg.Done()
}

func main() {
	taskChan := make(chan string)
	wg := sync.WaitGroup{}
	go func() {
		wg.Add(40)
		wg.Wait()
        close(taskChan)
	}()

	for i := 0; i < 40; i++ {
		go doRun(fmt.Sprintf("task-%d", i), taskChan, &wg)
	}

	for r := range taskChan {
		fmt.Println(r)
	}
	fmt.Println("Done")
}

请教各位程序大佬看看我 python 程序错在哪里？

第 1 条附言 · 2019-03-23 21:42:25 +08:00

看起来并不是 GIL 的事情啊，我是用 thread 原生写了一下，也是跟 go 版本一个级别的

```
import requests
from queue import Queue
from threading import Thread

class RunThread(Thread):
def __init__(self, task_name, queue):
super(RunThread, self).__init__(name=task_name)
self.task_name = task_name
self.queue = queue

def run(self):
resp = requests.get("http://localhost:8080")
self.queue.put(f"{self.task_name}-{resp.content}")

if __name__ == "__main__":
threads = []
q = Queue()
for i in range(40):
RunThread(f"task-{i}", q).start()

i = 0
while i < 40:
if q.empty():
continue
r = q.get()
print(r)
i += 1
```

`python thread-pyclient.py 3.91s user 0.16s system 86% cpu 4.678 total`

5 条回复