我在这里遇到了问题,我不知道我的代码有什么问题,但我在控制台中收到警告,如何删除此警告？
[Vue提示] ::
<todo-item v-for="todoItem in todos">使用v-for呈现的组件列表应具有显式键.有关详细信息,请参阅https://vuejs.org/v2/guide/list.html#key.
(找到<Root>)
的index.html
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Vue Tutorial</title>
<link rel="shortcut icon" href="https://vuejs.org/images/logo.png">
<script src="scripts/vue.js"></script>
</head>
<body>
<section id="app">
<p>{{ msg }}</p>
<p v-bind:title="message">
Hover your mouse over me for a few seconds to see my dynamically bound title!
</p>
<div>
<p v-if="seen">This text will show or hide if the button was clicked.</p>
<button type="button" v-on:click="isSeen">{{ isSeenText }}</button>
</div>
<ol>
<li v-for="todo in …这是我第一次在我的App中使用推送通知.我已经通过示例应用程序和书籍,我得到了如何将推送通知发送到单个设备.但我没有得到我应该在我的程序中做什么更改向多个设备发送推送通知.我正在使用"PushMeBaby"应用程序进行服务器端编码.拜托,帮帮我吧.提前致谢.
如果仅是如下所示的字符串串联，则立即完成。
test_str = "abcdefghijklmn123456789"
str1 = ""
str2 = ""
start = time.time()
for i in range(1, 100001):
str1 = str1 + test_str
str2 = str2 + test_str
if i % 20000 == 0:
print("time(sec) => {}".format(time.time() - start))
start = time.time()
恒定的处理时间
time(sec) => 0.013324975967407227
time(sec) => 0.020363807678222656
time(sec) => 0.009979963302612305
time(sec) => 0.01744699478149414
time(sec) => 0.0227658748626709
莫名其妙地，将串联字符串分配给另一个变量会使过程变得越来越慢。
test_str = "abcdefghijklmn123456789"
str1 = ""
str2 = ""
start = time.time()
for i in range(1, 100001):
str1 = str1 + …这是我的index.js文件:
const express = require('express')
const app = express()
app.set('views', __dirname + '/views');
app.set('view engine', 'pug')
app.get('/', function (req, res) {
res.render('index', { title: 'Hey', message: 'Hello there!' })
})
app.listen(3333, function () {
console.log('Example app listening on port 3333!')
})
index.pug文件:
html
head
title= title
body
h1= Hello
package.json文件:
{
"name": "@npm-private/pug_with_node",
"version": "1.0.0",
"description": "",
"main": "index.js",
"scripts": {
"test": "echo \"Error: no test specified\" && exit 1"
},
"keywords": [],
"author": "",
"license": "ISC",
"dependencies": {
"express": …运行此代码时,我在第一行遇到错误 App.propTypes
TypeError:无法读取未定义的属性"array"
码:
class App extends React.Component {
render() {
return (
<div>
<h3>Array: {this.props.propArray}</h3>
<h3>Array: {this.props.propBool ? "true" : "false"}</h3>
<h3>Func: {this.props.propFunc(3)}</h3>
<h3>Number: {this.props.propNumber}</h3>
<h3>String: {this.props.propString}</h3>
<h3>Object: {this.props.propObject.objectName1}</h3>
<h3>Object: {this.props.propObject.objectName2}</h3>
<h3>Object: {this.props.propObject.objectName3}</h3>
</div>
);
}
}
App.propTypes = {
propArray: React.PropTypes.array.isRequired, //I got error over here
propBool: React.PropTypes.bool.isRequired,
propFunc: React.PropTypes.func,
propNumber: React.PropTypes.number,
propString: React.PropTypes.string,
propObject: React.PropTypes.object
}
App.defaultProps = {
propArray: [1,2,3,4,5],
propBool: true,
propFunc: function(e){return e},
propNumber: 1,
propString: "String value...",
propObject: {
objectName1:"objectValue1",
objectName2: "objectValue2",
objectName3: …我正在尝试使用信号 python模块编写一个类来处理信号.有一个类的原因是避免使用全局变量.这是我提出的代码,但不幸的是它不起作用:
import signal
import constants
class SignalHandler (object):
def __init__(self):
self.counter = 0
self.break = False
self.vmeHandlerInstalled = False
def setVmeHandler(self):
self.vmeBufferFile = open('/dev/vme_shared_memory0', 'rb')
self.vmeHandlerInstalled = True
signal.signal(signal.SIGUSR1, self.traceHandler)
signal.siginterrupt(signal.SIGUSR1, False)
#...some other stuff...
def setBreakHandler(self):
signal.signal(signal.SIGINT, self.newBreakHandler)
signal.siginterrupt(signal.SIGINT, False)
def newBreakHandler(self, signum, frame):
self.removeVMEHandler()
self.break = True
def traceHandler(self, signum, frame):
self.counter += constants.Count
def removeVMEHandler(self):
if not self.vmeHandlerInstalled: return
if self.vmeBufferFile is None: return
signal.signal(signal.SIGUSR1, signal.SIG_DFL)
self.vmeHandlerInstalled = False
在主程序中,我以下列方式使用此类:
def run():
sigHandler = SignalHandler() …我在 GitLab 中创建了多个存储库。现在我想重命名或删除存储库。我怎样才能做到这一点？有可用的API吗？或者有没有可用的 git 命令？
这是我的代码:
var http = require('http');
var express = require('express');
var Session = require('express-session');
var google = require('googleapis');
var plus = google.plus('v1');
var OAuth2 = google.auth.OAuth2;
这是一个错误:
Error: Cannot find module 'googleapis'
at Function.Module._resolveFilename (module.js:485:15)
at Function.Module._load (module.js:437:25)
at Module.require (module.js:513:17)
at require (internal/module.js:11:18)
at Object.<anonymous> (/home/software/Harsh Patel/test/demo_auth/server.js:4:14)
at Module._compile (module.js:569:30)
at Object.Module._extensions..js (module.js:580:10)
at Module.load (module.js:503:32)
at tryModuleLoad (module.js:466:12)
at Function.Module._load (module.js:458:3)
我试图用这些方法重新安装模块
npm install googleapis --savenpm install googleapisnpm install (将模块添加到package.json文件中)但这些方法不起作用.
我在node_modules目录中找到了googleapis模块.
如您所知，GraphQL 没有像 long int 这样的数据类型。因此，每当数字像 一样大时10000000000，它就会抛出这样的错误：Int cannot represent non 32-bit signed integer value: 1000000000000
为此，我知道两种解决方案：
import { GraphQLScalarType } from 'graphql';
import { makeExecutableSchema } from '@graphql-tools/schema';
const myCustomScalarType = new GraphQLScalarType({
name: 'MyCustomScalar',
description: 'Description of my custom scalar type',
serialize(value) {
let result;
return result;
},
parseValue(value) {
let result;
return result;
},
parseLiteral(ast) {
switch (ast.kind) {
}
}
});
const schemaString = `
scalar MyCustomScalar
type Foo {
aField: MyCustomScalar
}
type …