我有以下代码
#include<stdio.h>
int main()
{
int a12345678901234567890123456789012345;
int a123456789012345678901234567890123456;
int sum;
scanf("%d",&a12345678901234567890123456789012345);
scanf("%d",&a123456789012345678901234567890123456);
sum = a12345678901234567890123456789012345 + a123456789012345678901234567890123456;
printf("%d\n",sum);
return 0;
}
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问题是,我们知道ANSI标准识别最多31个字符的变量......但是,两个变量最多相同,最多35个字符......但是,程序编译仍然没有任何错误和警告并给出正确的输出......
但是如何?
它不应该给出重新声明的错误吗?
如何在django过滤器中做小于或等于和大于等于?就像,我想获得价值: - 10<=val<=50在django视图.
为此,我在sql中使用了一些查询:
select count(*) from table_name where gender='MALE' and age<=50 and age>=10;
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我在django视图中尝试过类似的东西: -
tablename.objects.filter(Q(gender='MALE'),Q(age__lte=50) & Q(age__gte=10)).count()
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但我得到了不同的价值观.在sql我得到65和django我得到29. sql答案是正确的.请帮我在django视图中做比较.
我正在尝试使用pdfkit将网页转换为PDF,但它显示以下错误
Traceback (most recent call last):
File "<ipython-input-39-33289a2ef087>", line 1, in <module>
runfile('H:/Python/Practice/pdf_read_write.py', wdir='H:/Python/Practice')
File "C:\Program Files\Anaconda3\lib\site-packages\spyder\utils\site\sitecustomize.py", line 866, in runfile
execfile(filename, namespace)
File "C:\Program Files\Anaconda3\lib\site-packages\spyder\utils\site\sitecustomize.py", line 102, in execfile
exec(compile(f.read(), filename, 'exec'), namespace)
File "H:/Python/Practice/pdf_read_write.py", line 10, in <module>
config = pdfkit.configuration(wkhtmltopdf="C:\Program Files\wkhtmltopdf\bin\wkhtmltopdf.exe")
File "C:\Program Files\Anaconda3\lib\site-packages\pdfkit\api.py", line 83, in configuration
return Configuration(**kwargs)
File "C:\Program Files\Anaconda3\lib\site-packages\pdfkit\configuration.py", line 27, in __init__
'https://github.com/JazzCore/python-pdfkit/wiki/Installing-wkhtmltopdf' % self.wkhtmltopdf)
OSError: No wkhtmltopdf executable found: "C:\Program Files\wkhtmltopdin\wkhtmltopdf.exe"
If this file exists please check that this process can …Run Code Online (Sandbox Code Playgroud) 我有很多模型以某种方式相互引用,例如:
港口指的是城市,而城市又指的是国家。然后在 django admin 我想在 list_display Ports 国家显示:
class Country(models.Model):
title = models.CharField()
class City(models.Model):
title = models.CharField()
country = models.ForeignKey(Country)
class Port(models.Model):
city = models.ForeignKey(City)
def __str__(self):
return self.city.county.title
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所以基本上每个端口 django 都会生成更多的查询。我认为select_related在这种情况下会以某种方式帮助我,但是如何在模型中正确使用它?
我在地图上有两个连接点,我想知道哪个是起点和终点,所以我想添加路线的方向(箭头)。我如何使用 c# 来做到这一点?这是我的代码:
PointLatLng start1 = new PointLatLng(42.252938, 42.680411);
PointLatLng end1 = new PointLatLng(42.256321, 42.675658);
GDirections dir1;
var path1 = GMapProviders.GoogleMap.GetDirections(out dir1, start1, end1, false, false, true, true, true);
GMapRoute route1 = new GMapRoute(dir1.Route, "path1");
route1.Stroke.Color = Color.Red;
GMapOverlay lay1 = new GMapOverlay("route1");
lay1.Routes.Add(route1);
map.Overlays.Add(lay1);
Run Code Online (Sandbox Code Playgroud) 我使用 Monaca、Cordova 和 onsenUI 构建了一个基于 Vue.js 的应用程序。我想在我的页面中使用 Google 地图显示我的位置。为了实现这一点,我使用了一个npm包,vue2-google-maps但它没有显示任何内容。
我使用的代码来自软件包的官方文档。它们如下所示:
<template>
<v-ons-page>
<custom-toolbar>Page 1</custom-toolbar>
<div>
<gmap-map
:center="center"
:zoom="7"
style="width: 500px; height: 300px"
>
<gmap-marker
:key="index"
v-for="(m, index) in markers"
:position="m.position"
:clickable="true"
:draggable="true"
@click="center=m.position"
></gmap-marker>
</gmap-map>
</div>
</v-ons-page>
</template>
<script>
import * as VueGoogleMaps from 'vue2-google-maps';
import Vue from 'vue';
Vue.use(VueGoogleMaps, {
load: {
key: 'AIzaSyDX3SEHwFUY-k_Jp7YMp0-uTvo7up-paXM',
v: '3.26',
// libraries: 'places', //// If you need to use place input
}
});
export default {
data () { …Run Code Online (Sandbox Code Playgroud) 我在Playstore中有一个应用程序,我收到一些崩溃报告,大部分崩溃报告都包含IllegalArgumentException异常,这个异常并没有指向代码中的任何一行.我无法复制这个问题.任何人都可以帮我解决这个问题.
java.lang.IllegalArgumentException:
at android.support.v4.app.FragmentManagerImpl.moveToState (FragmentManager.java:1102)
at android.support.v4.app.FragmentManagerImpl.moveToState (FragmentManager.java:1290)
at android.support.v4.app.BackStackRecord.popFromBackStack (BackStackRecord.java:1038)
at android.support.v4.app.FragmentManagerImpl.popBackStackState (FragmentManager.java:1737)
at android.support.v4.app.FragmentManagerImpl.popBackStackImmediate (FragmentManager.java:605)
at android.support.v4.app.FragmentActivity.onBackPressed (FragmentActivity.java:179)
at android.app.Activity.onKeyUp (Activity.java:2755)
at android.view.KeyEvent.dispatch (KeyEvent.java:2712)
at android.app.Activity.dispatchKeyEvent (Activity.java:3056)
at android.support.v7.app.AppCompatActivity.dispatchKeyEvent (AppCompatActivity.java:543)
at android.support.v7.view.WindowCallbackWrapper.dispatchKeyEvent (WindowCallbackWrapper.java:53)
at android.support.v7.app.AppCompatDelegateImplBase$AppCompatWindowCallbackBase.dispatchKeyEvent (AppCompatDelegateImplBase.java:315)
at com.android.internal.policy.DecorView.dispatchKeyEvent (DecorView.java:319)
at android.view.ViewRootImpl$ViewPostImeInputStage.processKeyEvent (ViewRootImpl.java:4378)
at android.view.ViewRootImpl$ViewPostImeInputStage.onProcess (ViewRootImpl.java:4349)
at android.view.ViewRootImpl$InputStage.deliver (ViewRootImpl.java:3893)
at android.view.ViewRootImpl$InputStage.onDeliverToNext (ViewRootImpl.java:3946)
at android.view.ViewRootImpl$InputStage.forward (ViewRootImpl.java:3912)
at android.view.ViewRootImpl$AsyncInputStage.forward (ViewRootImpl.java:4039)
at android.view.ViewRootImpl$InputStage.apply (ViewRootImpl.java:3920)
at android.view.ViewRootImpl$AsyncInputStage.apply (ViewRootImpl.java:4096)
at android.view.ViewRootImpl$InputStage.deliver (ViewRootImpl.java:3893)
at android.view.ViewRootImpl$InputStage.onDeliverToNext (ViewRootImpl.java:3946)
at android.view.ViewRootImpl$InputStage.forward (ViewRootImpl.java:3912)
at android.view.ViewRootImpl$InputStage.apply (ViewRootImpl.java:3920)
at …Run Code Online (Sandbox Code Playgroud) 我正在尝试使用以下方法并行运行 Django 测试:
python manage.py test --keepdb --parallel
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但是,如果测试失败,则会导致 SQL 连接中止。在 MySQL 中,我可以看到它:
SHOW GLOBAL STATUS LIKE 'Aborted_connects'; -- aborted_connects : 1
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正因为如此,我在其他测试中不断看到这个错误:
django.db.utils.OperationalError: (2013, "Lost connection to MySQL server at 'reading initial communication packet', system error: 102")
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我该怎么做才能避免这种情况?这是其他测试失败的示例回溯:
Using existing test database for alias 'default'...
Traceback (most recent call last):
File "/Applications/PyCharm.app/Contents/helpers/pycharm/django_test_manage.py", line 157, in <module>
utility.execute()
File "/Applications/PyCharm.app/Contents/helpers/pycharm/django_test_manage.py", line 132, in execute
PycharmTestCommand().run_from_argv(self.argv)
File "/Users/dio/.virtualenvs/athena/lib/python2.7/site-packages/django/core/management/commands/test.py", line 30, in run_from_argv
super(Command, self).run_from_argv(argv)
File "/Users/dio/.virtualenvs/athena/lib/python2.7/site-packages/django/core/management/base.py", line 348, in run_from_argv
self.execute(*args, …Run Code Online (Sandbox Code Playgroud) 在javascript中执行以下代码时:
var name=["Pankaj","Kumar"] ;
for( var i=0;i<name.length;i++)
{
console.log("Hello "+name[i]);
}
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据我说,它应该输出:
Hello Pankaj
Hello Kumar
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但是javascript引擎输出:
Hello P
Hello a
Hello n
Hello k
Hello a
Hello j
Hello ,
Hello K
Hello u
Hello m
Hello a
Hello r
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如果我们将数组名称更改为名称,则根据预期输出:
Hello Pankaj
Hello Kumar
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name不是javascript保留的关键字.
你能告诉我这种行为的原因吗?
django ×4
python ×4
google-maps ×2
javascript ×2
android ×1
arrays ×1
c ×1
c# ×1
cordova ×1
django-orm ×1
java ×1
monaca ×1
moodle ×1
mysql ×1
pdfkit ×1
php ×1
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