第四篇用Django创建后端

关键词

Django Python

GitHub

创建project

Django的文档非常的详细，参考这个就可以
Django创建project

这里咱们创建一个app叫stockserver

django-admin startproject mysite
python manage.py startapp stockserver

在mysite/settings.py的INSTALLED_APPS加上stockserver

INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    'stockserver'
]

配置跨域中间件

因为我们最后用Vue做前端，需要解决跨域的问题，需要安装django-cors-headers

pip install django-cors-headers

在mysite/settings.py的MIDDLEWARE加上corsheaders，注意顺序，越靠前越好，尤其是在Django的CommonMiddleware前。
然后还有一些其他的设置。

MIDDLEWARE = [
    'django.middleware.security.SecurityMiddleware',
    'django.contrib.sessions.middleware.SessionMiddleware',
    'corsheaders.middleware.CorsMiddleware',
    'django.middleware.common.CommonMiddleware',
    'django.middleware.csrf.CsrfViewMiddleware',
    'django.contrib.auth.middleware.AuthenticationMiddleware',
    'django.contrib.messages.middleware.MessageMiddleware',
    'django.middleware.clickjacking.XFrameOptionsMiddleware',
]

CORS_ALLOW_CREDENTIALS = True
CORS_ORIGIN_ALLOW_ALL = True
CORS_ORIGIN_WHITELIST = (
    '*'
)

CORS_ALLOW_METHODS = (
    'DELETE',
    'GET',
    'OPTIONS',
    'PATCH',
    'POST',
    'PUT',
    'VIEW',
)

CORS_ALLOW_HEADERS = (
    'XMLHttpRequest',
    'X_FILENAME',
    'accept-encoding',
    'authorization',
    'content-type',
    'dnt',
    'origin',
    'user-agent',
    'x-csrftoken',
    'x-requested-with',
    'Pragma',
)

配置路由

设置mysite/urls.py, 将stockserver的urls加入project的urls

from django.contrib import admin
from django.urls import path
from django.conf.urls import include

urlpatterns = [
    path('admin/', admin.site.urls),
    path('stockserver/', include('stockserver.urls')),
]

实现stockserver

其实Django最好是用model来对应数据库，但是考虑到这个项目只需要拿股票日K数据和指标数据，直接pd.read_sql()更方便，所以就不设置model了

获取股票指标

输入是前端传过来的request，需要传递specname，order和abs，这里我们设置一些默认值。
这里specname就是第二篇里创建数据库的stock_spec表的那一些列名，像贝塔系数这个正和负都表示跟大盘偏离比较大，所以需要加abs，大多数参数不需要加abs。
limit 0,50 就是取最大或最小的50只股票, 然后用DataFrame.to_json方法生成json格式返回前端。注意to_json方法里的orient参数，根据自己的需求来设置。

# stockserver/views.py
def spec(request):
    specname = request.GET.get('specname', 'amplitude_10')
    order = request.GET.get('order', 'desc')
    isAbs = request.GET.get('abs', 'false')
    orderbyvalue = specname
    if isAbs == 'true':
        orderbyvalue = "abs(" + specname + ")"
    print(specname, order, isAbs, orderbyvalue)
    cx = sqlite3.connect(r'D:\codes\python\stock\mystock.db')
    sql_cmd = "SELECT * FROM stock_spec where date=(select max(date) from stock_spec) and " + specname + " != 'NaN' order by " + orderbyvalue + " " + order + " limit 0,50"
    
    result = pd.read_sql(sql=sql_cmd, con=cx)
    df_json = result.to_json(orient = 'table', force_ascii = False)
    data = json.loads(df_json)

    return JsonResponse(data, safe=False)

获取股票日k

# stockserver/views.py
def dayk(request):
    codename = request.GET.get('code', 'sh.000001')
    order = 'desc'
    print(codename, order)
    cx = sqlite3.connect(r'D:\codes\python\stock\mystock.db')
    sql_cmd = "SELECT * FROM stock_day_k where code='" + codename +"' order by date desc limit 0,365"
    
    result = pd.read_sql(sql=sql_cmd, con=cx)
    df_json = result.to_json(orient = 'table', force_ascii = False)
    data = json.loads(df_json)

    return JsonResponse(data, safe=False)

配置路由

#stockserver/urls.py
from django.urls import path
from . import views

urlpatterns = [
    path('', views.index),
    path('spec/', views.spec),
    path('dayk/', views.dayk),
]

运行

python manage.py runserver

然后在浏览器输入 127.0.0.1:8000/stockserver/spec 应该就能看到返回的json数据。

最后编辑于：2021.08.07 01:32:52

第四篇 用Django创建后端

关键词