关于python:Python人工智能就业班v50wumi

download:Python+人工智能待业班v5.0

package main
import (

"fmt""math/rand""time"

)
var (

Web   = fakeSearch("web")Image = fakeSearch("image")Video = fakeSearch("video")

)
type Result string
type Search func(query string) Result
func fakeSearch(kind string) Search {

return func(query string) Result {    time.Sleep(time.Duration(rand.Intn(100)) * time.Millisecond)    return Result(fmt.Sprintf("%s result for %q\n", kind, query))}

}
func Google(query string) (results []Result) {

results = append(results, Web(query))results = append(results, Image(query))results = append(results, Video(query))return

}
func main() {

rand.Seed(time.Now().UnixNano())start := time.Now()results := Google("golang")elapsed := time.Since(start)fmt.Println(results)fmt.Println(elapsed)

}
运行后果如下:

[web result for "golang"
image result for "golang"
video result for "golang"
]
153.365484ms

谷歌搜寻2.0

同时运行网页、图像和视频搜寻，并等待所有后果。没有锁，没有条件变量，没有回调。

代码如下，关注Google函数。

package main
import (

"fmt""math/rand""time"

)
var (

Web   = fakeSearch("web")Image = fakeSearch("image")Video = fakeSearch("video")

)
type Result string
type Search func(query string) Result
func fakeSearch(kind string) Search {

return func(query string) Result {    time.Sleep(time.Duration(rand.Intn(100)) * time.Millisecond)    return Result(fmt.Sprintf("%s result for %q\n", kind, query))}

}
func Google(query string) (results []Result) {

c := make(chan Result)go func() { c <- Web(query) } ()go func() { c <- Image(query) } ()go func() { c <- Video(query) } ()for i := 0; i < 3; i++ {    result := <-c    results = append(results, result)}return

}
func main() {

rand.Seed(time.Now().UnixNano())start := time.Now()results := Google("golang")elapsed := time.Since(start)fmt.Println(results)fmt.Println(elapsed)

}

谷歌搜寻2.1 不要等待缓慢的服务器。没有锁，无条件变量，没有回调。通过select的超时实现，需要把time.After定义的超时通道放在for循环外层。

package main
import (

"fmt""math/rand""time"

)
var (

Web   = fakeSearch("web")Image = fakeSearch("image")Video = fakeSearch("video")

)
type Result string
type Search func(query string) Result
func fakeSearch(kind string) Search {

return func(query string) Result {    time.Sleep(time.Duration(rand.Intn(100)) * time.Millisecond)    return Result(fmt.Sprintf("%s result for %q\n", kind, query))}

}
func Google(query string) (results []Result) {

c := make(chan Result)go func() { c <- Web(query) } ()go func() { c <- Image(query) } ()go func() { c <- Video(query) } ()timeout := time.After(80 * time.Millisecond)for i := 0; i < 3; i++ {    select {    case result := <-c:        results = append(results, result)    case <-timeout:        fmt.Println("timed out")        return    }}return

}
func main() {

rand.Seed(time.Now().UnixNano())start := time.Now()results := Google("golang")elapsed := time.Since(start)fmt.Println(results)fmt.Println(elapsed)

}