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The thread pool of futuers in python3 is very efficient, but sometimes I wonder if it can be realized if it is a little slower, such as an interval of 0.5 between tasks.
The question is written on the title, is there any way to be spaced by BAN, when it is applied too fast in crawlers? Or is it that there is no interval in this kind of concurrency? ...
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Is the middleware Synchronize in the koa2 framework or asynchronous?
question 1: why is the middleware in the koa2 framework written in the form of async, rarely in Synchronize mode (that is, without async)? For example,
app.use(async (ctx, next) => {
const start = new Date()
await next()
const ms = new Date() ...
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Asynchronously request data, according to the request data require component
I am working on a page customization function. The template is stored in the background database, so you need to pull the template id, from the background and then follow the template id require corresponding to the components in the directory. For exam...
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Doubts about the nesting of setTimeout Multi-layer callback functions
I am a novice. I encountered some doubts when learning the asynchronism of javascript , as follows: there is an example code like this in teacher Ruan Yifeng s tutorial:
does not particularly understand the operation mechanism of the whole mult...
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Dom does not render the changes of all the attributes in the watch array in Vue.
1.data defines the array gametasks, 2.wacth. Console can see that the data has indeed changed. 3. Rendering is not successful in dom
...
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Async / Await in IIFF (execute the function immediately)
it is expected that the following code should be printed in the order of 1 2 3 4 5, but when it is actually executed, it is 1 2 5 3 4 4
(async () => {
console.log("1");
let n = await new Promise((reslove, reject) => {
console.lo...
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I would like to ask how to return the data after asynchronous operation when performing asynchronous operation in foreach?
the code is as follows:
function longTimeDo() {
let data = [];
let sourse = [1,2,3,4,5];
sourse.forEach(value=>{
setTimeout(()=>{
data.push(value);
},1000);
});
?data
}
...
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On the structure of Import Table of aiomysql and sqlalchemy
import asyncio
import sqlalchemy as sa
from aiomysql.sa import create_engine
@asyncio.coroutine
def go():
engine = yield from create_engine(user= root ,db= test ,host= 127.0.0.1 ,password= root )
metadata = sa.MetaData(bind=engine)
...
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How does nodejs return data asynchronously?
The row of asterisks will print out that the data that should be return in the undefined, search function has the data I need, and there is no data on the page. Where is the problem?
the data format of the page request is
async function search(sear...
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Questions about the use of js async
originally wrote JAVA, but the sophomore recently encountered asynchronous programming in the new nodejs, is a bit difficult to understand.
now I am writing a crawler originally done in JAVA, get a url list, submit the request crawl web page with for...
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How to deal with the asynchronous result of node.js export
the project obtains the configuration items through the configuration file before it wants to go to devops,. Now it pulls the configuration items from the configuration center, modifies the previous configuration file Synchronize load to obtain the con...
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Ajax loop call problem, very anxious, ask the seniors to have a look
I need to get monthly statistics, and then the statistical cloud returns daily. So I passed the reference time for 12 months respectively. Call 12 times to get the total count for each month. Each time the resulting value is assigned to an array month. ...
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Asynchronous problem async-awit
this problem is difficult to describe, but I ll try to
,orm(typeOrm),mockProjectPanorama(ProjectPanorama)
3Panorama(mockData.defaultPanoramas)
3Panorama3ProjectPanorama
ProjectPanorama
projectId
panoramaId
1
3
1
3
1
3
3panorama,
,le...
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How to control the execution order by calling promise in forEach
recently, I am doing a web crawler, first grab the list page, then get the url, of all the content pages of the list page, and then call the url loop of all the list pages to the crawling method, which leads to the uncontrollable crawling order. I want ...
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Why do two ashx, requests always return together when the slowest ashx completes?
ASP.NET project, two classes An and B are implemented since IHttpHandler,A normally takes 3 seconds, and B takes 3 seconds. On the client side, two threads are used to request An and B respectively. Through fiddler packet grab observation, the request ti...
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Nodejs arr.prototype.map cannot add object properties
PageTagMapModel.getPageTagMapNum ({tag: single._id, status: normal }) returns the page_num found by the mongoose query, but if three lines of comments are used in the code, there is no page_num attribute in the resulting data. You can use = to assig...
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The problem of execution sequence of python collaboration programs
problem description:
when I was working on the actual combat article of Liao Xuefeng, I had a question when operating the database. I first defined two co-programs, and then defined a main co-program await to execute the two co-programs sequentially...
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How Promise does not return the promise object, but directly returns the value of resolve
functiong getPromise(){
return Promise.resolve( something );
}
let getSomething = async function(){
let a = await getPromise();
return a;
}
The async function returns a promise object, so there is no way to return a non-promise ob...
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Vue Asynchronous component problem
learn the content of vue asynchronous component, and write the simplest asynchronous component demo
:
:
:
:
js .
have you ever encountered similar problems, please help solve
webpack version 4.8.3,
...
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Mini Program's question of asynchronously obtaining wx.request data
WeChat Mini Programs s wx.request is an asynchronous request. Perform background interaction in app.js onLaunch to obtain openid
APP({
onLaunch:function(){
wx.login({
success:res => {
var code = re...