对于算法的计时(大约以ms为单位),这两种方法中的哪一种更好:
clock_t start = clock();
algorithm();
clock_t end = clock();
double time = (double) (end-start) / CLOCKS_PER_SEC * 1000.0;
要么,
time_t start = time(0);
algorithm();
time_t end = time(0);
double time = difftime(end, start) * 1000.0;
另外,根据Freenode的C++频道中的一些讨论,我知道时钟的分辨率非常差,因此(相对)快速算法的时序将为零.但是,哪个有更好的分辨率time()或clock()？还是一样吗？
哪种是最佳实践(在本例中):
bool Foo::operator==(const Foo& other) {
return bar == other.bar;
}
// Implementation 1
bool Foo::operator!=(const Foo& other) {
return bar != other.bar
}
// Implementation 2
bool Foo::operator!=(const Foo& other) {
return !(*this == other);
}
对于像>,<,<=,> =这样的运算符,我会尽可能使用实现2.但是,对于!=我认为实现1更好,因为没有进行另一个方法调用,这是正确的吗？
是什么区别定义和类定义的开始初始化的成员变量,并首先定义的成员变量,并在构造函数初始化成员变量？
比方说,例如:
public class Test {
private int foo = 123;
private boolean flag = false;
public void fooMethod() {...}
}
与:
public class Test {
private int foo;
private boolean flag;
public Test() {
foo = 123;
flag = false;
}
public void fooMethod() {...}
}
提前致谢.
我跑了heroku push master,得到了这个:
----- Python app detected
----- No runtime.txt provided; assuming python-2.7.3.
----- Using Python runtime (python-2.7.3)
----- Installing dependencies using Pip (1.2.1)
Downloading/unpacking Django-1.5c2 from https://www.djangoproject.com/download/1.5c2/tarball (from -r
requirements.txt (line 1))
Cannot determine compression type for file /tmp/pip-rYIGHS-unpack/tarball.ksh
Running setup.py egg_info for package Django-1.5c2
Installing collected packages: Django-1.5c2
Running setup.py install for Django-1.5c2
changing mode of build/scripts-2.7/django-admin.py from 600 to 755
changing mode of /app/.heroku/python/bin/django-admin.py to 755
========
WARNING!
========
You have just installed Django over …我无法使用AJAX将结果显示在Select2中.这是我的代码:
$(document).ready(function() {
$("#producto").select2({
placeholder: 'Select a product',
formatResult: productFormatResult,
formatSelection: productFormatSelection,
dropdownClass: 'bigdrop',
escapeMarkup: function(m) { return m; },
minimumInputLength:3,
ajax: {
url: 'http://foo.foo/listar.json',
dataType: 'jsonp',
data: function(term, page) {
return {
q: term
};
},
results: function(data, page) {
return {results:data};
}
}
});
function productFormatResult(product) {
var html = "<table class='product-resultado'><tr>";
if(product.img != undefined) {
html += "<td class='product-image'><img src='"+product.img+"'/></td>";
}
html += "<td class='product-info'>";
html += product.text + "<br />";
html += product.precio_costo + " CRC …我收到以下错误:
django.core.exceptions.ImproperlyConfigured:模块"accounts.forms"没有定义"SignupForm"类
settings.py
(...)
ACCOUNT_SIGNUP_FORM_CLASS = 'accounts.forms.SignupForm'
(...)
账户/ forms.py
from allauth.account.forms import BaseSignupForm
class SignupForm(BaseSignupForm):
def __init__(self, *args, **kwargs):
self.sociallogin = kwargs.pop('sociallogin')
user = self.sociallogin.account.user
first_name = forms.CharField(label=_('First name'),
max_length=30,
min_length=2,
widget=forms.TextInput(attrs={
'placeholder':_('First name')}))
last_name = forms.CharField(label=_('Last name'),
max_length=30,
min_length=2,
widget=forms.TextInput(attrs={
'placeholder':_('Last name')}))
second_last_name = forms.CharField(label=_('Second last name'),
max_length=30,
empty='',
widget=forms.TextInput(attrs={
'placeholder':_('Second last name')}))
# TODO: Should become more generic, not listing
# a few fixed properties.
initial = {'email': user_email(user) or '',
'username': user_username(user) or '',
'first_name': user_field(user, …我正在尝试使用django-allauth进行用户注册.我有这个表格
class UserProfileForm(forms.ModelForm):
class Meta:
model = UserProfile
fields = ('gender', 'country', 'city', 'birth_date', 'has_accepted_tos')
并根据我在settings.py中设置的说明
ACCOUNT_SIGNUP_FORM_CLASS = "userprofile.forms.UserProfileForm"
问题是,当表单呈现我的自定义表单要求性别,国家等呈现在顶部,然后标准用户字段,要求用户名,电子邮件和密码.这个顺序的东西:
密码2
我想按此顺序显示字段
用户名
我目前正在使用AWS ElasticBeanstalk中的单个容器 docker 环境部署Django + uWSGI应用程序。这个环境已经随nginx一起提供了，我目前正在尝试配置它。
我正在努力实现以下目标：
环境信息：
这是我当前的配置：
.ebxtensions / 00-负载平衡器终止https.config
option_settings:
aws:elb:listener:443:
ListenerEnabled: true
ListenerProtocol: HTTPS
SSLCertificateId: <resource-id-here>
InstancePort: 443
InstanceProtocol: HTTP
aws:elb:listener:80:
ListenerEnabled: true
ListenerProtocol: HTTP
InstancePort: 80
InstanceProtocol: HTTP
.ebextensions / 01-nginx-proxy.config
files:
"/etc/nginx/sites-available/test.domain.com.conf":
mode: "000644"
owner: root
group: root
content: |
server {
listen 80;
server_name test.domain.com;
access_log /var/log/nginx/$server_name.access.log;
location / {
return 301 https://$server_name$request_uri; …nginx amazon-web-services uwsgi docker amazon-elastic-beanstalk
我正在尝试创建一个指向私有成员函数的数组.阵列本身是私有的,所以我不明白为什么它说:
错误:'void Foo :: foo1(int)'是私有的
这有效:
class Foo {
public:
Foo();
void foo1(int);
void foo2(int);
private:
void (Foo::*someMethods[])(int);
void foo3(int);
};
Foo::Foo() {}
void (Foo::*someMethods[])(int) = {&Foo::foo1, &Foo::foo2};
void Foo::foo1(int) {}
void Foo::foo2(int) {}
void Foo::foo3(int) {}
这不起作用:
class Foo {
public:
Foo();
private:
void (Foo::*someMethods[])(int);
void foo1(int);
void foo2(int);
void foo3(int);
};
Foo::Foo() {}
void (Foo::*someMethods[])(int) = {&Foo::foo1, &Foo::foo2};
void Foo::foo1(int) {}
void Foo::foo2(int) {}
void Foo::foo3(int) {}
我需要使用django-restframework-bulk mixins将对象列表发送到视图:
class APIPicksView(mixins.ListModelMixin,
bulk_mixins.BulkCreateModelMixin,
generics.GenericAPIView):
def get(self, request, *args, **kwargs):
return self.list(request, *args, **kwargs)
def post(self, request, *args, **kwargs):
print(type(request.DATA)) /* Should be list */
if isinstance(request.DATA, list):
# Custom logic here
在浏览器端,我正在尝试发送一个对象的数组(列表):
var csrftoken = $.cookie('csrftoken');
var data = [];
for(var i = 0; i < picks.length; ++i) {
data.push({pick:picks[i], priority:i, user:null});
}
$.ajax({
type:"POST",
url: "/api/foo/picks/",
data: /* How should I format this data? */,
sucess: function() { alert("Success!"); },
dataType: "json",
traditional:false, /* Should this be …