限制访问次数例子和Ajax的some

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-- 限制访问次数作业解答 --
-- urls.py 里--
from django.conf.urls import url
from django.contrib import admin
from app01 import views
urlpatterns = [
url(r'^admin/', admin.site.urls),
url(r'^index/', views.index),]-- views.py 里--
from django.shortcuts import render, HttpResponse
def index(request):
return HttpResponse('index')-- 代码写在哪里? 限制次数 --
新建文件夹 middleware --> my_middleware.py里
在 settings.py 里注册中间件 'middleware.my_middleware.Throttle'
导入类
from django.utils.deprecation import MiddlewareMixin
from django.shortcuts import HttpResponse
import timevisit_dict = {}
-- 普通版 --
class Throttle(MiddlewareMixin): 节流器
def process_request(self, request):
ip = request.META.get('REMOTE_ADDR')
now = time.time()
# 获取访问的记录
history = visit_dict.get(ip, [])
# 根据记录进行判断 [ 10:06:05,10:06:09,10:06:45 ]
new = []
for i in history:
if now - i < 5:
new.append(i)
history = new
if len(history) >= 3:
return HttpResponse('访问频率太快了，你先歇一会')
history.append(now)
visit_dict[ip] = history-- 优化版--
def process_request(self, request):
ip = request.META.get('REMOTE_ADDR')
now = time.time()
# 获取访问的记录
history = visit_dict.get(ip, [])
# 根据记录进行判断 [ 10:06:45,10:06:09,10:06:05, ]
while history and now - history[-1] > 5:
history.pop() #删除最后一个
if len(history) >= 3:
return HttpResponse('访问频率太快了，你先歇一会')
history.insert(0, now)
visit_dict[ip] = history
-- session 版 -- 一个浏览器就是一个用户
def process_request(self, request):
now = time.time() #拿到当前时间
# 获取访问的记录
history = request.session.get('history', [])
# 根据记录进行判断 [ 10:06:45,10:06:09,10:06:05, ]
while history and now - history[-1] > 5:
history.pop()
if len(history) >= 3:
return HttpResponse('访问频率太快了，你先歇一会')
history.insert(0, now)
request.session['history'] = history
数据库没表 python manage.py migrate 数据库迁移命令
django_session表一个浏览器就是一个记录

-- html -- ajax参数的问题
$.ajax({
url: '/ajax_test/', 提交地址
type: 'get', 类型
data: { 数据
name: 'alex', 键值对
age: 73,
hobby: JSON.stringify(['大保健', 'cnb', '画大饼'])
},
success: function (res) { 回调函数
console.log(res)
},
error: function (res) { 错误
console.log(res)
}
})-- views.py --from django.conf import global_settings
import json
from django.http import JsonResponsedef ajax_test(request): print(request.POST) hobby = request.POST.get('hobby') # 拿到字符串的东西
hobby = json.loads(hobby) # 反序列化
print(hobby, type(hobby)) # 列表 list # return HttpResponse(json.dumps({'xxx':'xxxx'})) # text/html; charset=utf-8
return JsonResponse({'xxx': 'xxxx'}) # content_type: application/json'
# return JsonResponse([],safe=False) # content_type: application/json'
复制代码

上传文件 upload

-- html --
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
<form action="" enctype="multipart/form-data"></form>
**<form action="" enctype="application/x-www-form-urlencoded"></form>** 删除这行
<input type="file" id="f1">
<button id="b1">上传</button><script src="https://cdn.bootcss.com/jquery/3.3.1/jquery.js"></script>
<script>
$('#b1').click(function () {
var form_obj = new FormData(); #组建FormData对象
form_obj.append('x1', $('#f1')[0].files[0]); #jQuery对象到DOM对象--键,值
$.ajax({
url: '/upload/',
type: 'post',
data: form_obj,
processData:false, #注意不处理编码方式
contentType:false, #注意不处理请求头
success: function (res) {
alert('OK')
}
})
})
</script>
</body>
</html>-- views.py -- 此时注释csrf中间件
def upload(request):
if request.is_ajax(): #是的话就返回True
file_obj = request.FILES.get('x1')
with open(file_obj.name, 'wb') as f:
for i in file_obj.chunks():
f.write(i)
return HttpResponse('ok')
return render(request, 'upload.html')

csrf 校验

-- 发 ajax 能提交 post 请求 --
保证有cookie{% csrf_token %} 两个作用:一个是隐藏的标签,另一个检查里能看到cookie了
方法一:
$.ajax({
url: '/calc/',
type: 'post',
data: { csrfmiddlewaretoken:$('[name="csrfmiddlewaretoken"]').val() , #属性选择器
i1: $('[name="i1"]').val(),
i2: $('[name="i2"]').val(),
},
success: function (res) {
$('[name="i3"]').val(res)
}
})
方法二:
装饰器
from django.views.decorators.csrf import ensure_csrf_cookie #确保访问某个视图有csrf_cookie
@ensure_csrf_cookie
def func(request):
pass
设置请求头
$('#b2').click(function () {
$.ajax({
url: '/calc2/',
type: 'post',
headers:{
'X-csrftoken': $('[name="csrfmiddlewaretoken"]').val(),
},
data: {
i1: $('[name="ii1"]').val(),
i2: $('[name="ii2"]').val(),
},
success: function (res) {
$('[name="ii3"]').val(res)
}
})
});
推荐以后的用法 -- 引入静态文件,配置静态文件 --批量操作
static --> js -->ajax_setup.js
function getCookie(name) {
var cookieValue = null;
if (document.cookie && document.cookie !== '') {
var cookies = document.cookie.split(';');
for (var i = 0; i < cookies.length; i++) {
var cookie = jQuery.trim(cookies[i]);
// Does this cookie string begin with the name we want?
if (cookie.substring(0, name.length + 1) === (name + '=')) {
cookieValue = decodeURIComponent(cookie.substring(name.length + 1));
break;
}
}
}
return cookieValue;
}
var csrftoken = getCookie('csrftoken');
function csrfSafeMethod(method) {
// these HTTP methods do not require CSRF protection
return (/^(GET|HEAD|OPTIONS|TRACE)$/.test(method));
} #正则表达式匹配
$.ajaxSetup({
beforeSend: function (xhr, settings) {
if (!csrfSafeMethod(settings.type) && !this.crossDomain) {
xhr.setRequestHeader("X-CSRFToken", csrftoken);
}
}
});
页面引用
<script src="/static/js/ajax_setup.js"></script>
这样每个ajax都可以发送post请求了