首页 > > 网络编程 > 其它 >

Python：Django框架开发数据可视化网站

2018-06-18 03:15:32来源：未知阅读 ()

Step 0: 使用新的 virtualenv 环境

建议使用 1.11.4 版本的 Django

$ virtualenv --no-site-packages pyecharts-env
$ source pyecharts-env/bin/activate
$ pip install django==1.11.4
$ pip install pyecharts

Step 1: 新建一个 django 项目

$ django-admin startproject myechartsite

创建一个应用程序

$ python manage.py startapp myfirstvis
$ ls
db.sqlite3      manage.py       myechartsite    myfirstvis

在 myechartsite/settings.py 中注册应用程序

# myechartsite/settings.py
INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    'myfirstvis'  # <---
]

我们先编辑 urls.py.这文件在 Django 里的功能是把前段的 HTTP 需求和后台服务函数挂钩。在 Step3，我们再引入后端服务函数

1 # myfirstvis/urls.py
2 from django.conf.urls import url
3 
4 from . import views
5 
6 urlpatterns = [
7     url(r'^$', views.index, name='index'),
8 ]

在 myechartsite/urls.py 中新增 'myfirstvis.urls'

1 myechartsite/urls.py
2 from django.conf.urls import include, url
3 from django.contrib import admin
4 
5 urlpatterns = [
6     url(r'^admin/', admin.site.urls),
7     url(r'myfirstvis/', include('myfirstvis.urls'))  # <---
8 ]

Step 2: 处理视图功能部分

将下列代码保存到 myfirstvis/views.py 中。

 1 from __future__ import unicode_literals
 2 import math
 3 
 4 from django.http import HttpResponse
 5 from django.template import loader
 6 from pyecharts import Line3D
 7 
 8 
 9 REMOTE_HOST = "https://pyecharts.github.io/assets/js"
10 
11 
12 def index(request):
13     template = loader.get_template('myfirstvis/pyecharts.html')
14     l3d = line3d()
15     context = dict(
16         myechart=l3d.render_embed(),
17         host=REMOTE_HOST,
18         script_list=l3d.get_js_dependencies()
19     )
20     return HttpResponse(template.render(context, request))
21 
22 
23 def line3d():
24     _data = []
25     for t in range(0, 25000):
26         _t = t / 1000
27         x = (1 + 0.25 * math.cos(75 * _t)) * math.cos(_t)
28         y = (1 + 0.25 * math.cos(75 * _t)) * math.sin(_t)
29         z = _t + 2.0 * math.sin(75 * _t)
30         _data.append([x, y, z])
31     range_color = [
32         '#313695', '#4575b4', '#74add1', '#abd9e9', '#e0f3f8', '#ffffbf',
33         '#fee090', '#fdae61', '#f46d43', '#d73027', '#a50026']
34     line3d = Line3D("3D line plot demo", width=1200, height=600)
35     line3d.add("", _data, is_visualmap=True,
36                visual_range_color=range_color, visual_range=[0, 30],
37                is_grid3D_rotate=True, grid3D_rotate_speed=180)
38     return line3d

cript_list 是 Page() 类渲染网页所需要依赖的 echarts js 库，依赖的库的数量取决于所要渲染的图形种类。

host 是 echarts js 库的地址，默认提供的地址为 https://pyecharts.github.io/assets/js 当然，如果你愿意你也可以改变这个地址，先克隆 https://github.com/pyecharts/assets 然后将 js 文件夹挂载在你自己的服务器上即可。

Step 3: 为项目提供自己的模板

Windows 系统

在 myfirstvis 目录下，新建 templates/myfirstvis 子目录

myfirstvis 目录

─ myfirstvis
    ├── admin.py
    ├── apps.py
    ├── __init__.py
    ├── migrations
    │   ├── __init__.py
    ├── models.py
    ├── templates
    │   └── myfirstvis
    │       └── pyecharts.html
    ├── tests.py
    ├── urls.py
    └── views.py

将下面 html 模板代码保存为 pyecharts.html，请确保 pyecharts.html 文件的绝对路径为 <project root>/myfirstvis/templates/myfirstvis

 1 <!-- myfirstvis/templates/pyecharts.html -->
 2 <!DOCTYPE html>
 3 <html>
 4 
 5 <head>
 6     <meta charset="utf-8">
 7     <title>Proudly presented by PycCharts</title>
 8     {% for jsfile_name in script_list %}
 9         <script src="{{ host }}/{{ jsfile_name }}.js"></script>
10     {% endfor %}
11 </head>
12 
13 <body>
14   {{ myechart|safe }}
15 </body>
16 
17 </html>

Step 4: 运行项目

$ cd myechartsite
$ python manage.py runserver

You have 13 unapplied migration(s). Your project may not work properly until you apply the migrations for app(s): admin, auth, contenttypes, sessions.
Run 'python manage.py migrate' to apply them.

August 08, 2017 - 05:48:38
Django version 1.11.4, using settings 'myechartsite.settings'
Starting development server at http://127.0.0.1:8000/
Quit the server with CONTROL-C.