ColinSpace Site

Django restframework 实现批量操作(新增、修改、删除)

2022-04-19发表Django1 分钟读完 (大约171个字)

通过自定义方式在view中自定义批量更新和删除的方法，主要是用到rest_framework中的action装饰器；此外也介绍另外一个更优雅的方案，采用 restframework-bulk 模块

django 实现分页

2022-04-02发表Django4 分钟读完 (大约615个字)

1、函数视图分页

from django.core.paginator import Paginator
from django.shortcuts import render
from .models import Post 

def index(request):
    posts = Post.objects.all()
    paginator = Paginator(posts, 15)
    # 默认一般都是使用page参数
    page_number = request.GET.get('page')
    page_obj = paginator.get_page(page_number)
    return render(request, 'blog/index.html', {'page_obj': page_obj})

2、类视图分页

from django.views.generic import ListView
from .models import Post 

class IndexListView(ListView):
    # 关联模型
    model = Post
    # 模板名称，默认推导为 index_list.html
    template_name = 'blogv3/index.html'
    # 模板中的对象名称，默认为 object_list
    context_object_name = 'posts'
    # 限制请求方法
    http_method_names = ['get']
    # 设置分页
    paginate_by = 15
    
    # 可以通过get_context_data获取到分页信息，当然前提是设置了 paginate_by
    # def get_context_data(self, *args, **kwargs):
    #     context = super().get_context_data(*args, **kwargs)
    #     print(context)
    #     return context

上述调试中获取的到context内容为

{
	'paginator': <django.core.paginator.Paginator object at 0x104ff4160>, 
  'page_obj': <Page 1 of 4>, 
  'is_paginated': True, 
  'object_list': <QuerySet [... ...]>, 
  'view': <blogv3.views.IndexListView object at 0x104ff43a0>
  }

说明：

paginator Django的分页对象
page_obj 当前页参数，实际在template中判断的时候使用的就是该对象
is_paginated 是否分页
object_list 对象名称，context_object_name 定义了posts ，两者效果等效
view 视图名称

template中配置实际分页信息

<div class="container navigation">
    {% if page_obj.has_previous %}
    <a class="navigate pull-left" href="?page={{ page_obj.previous_page_number }}"><i class="fa fa-caret-left"></i> <<< 更 新</a>
    {% endif %}
      
    <!-- 当然有时候这里也可以显示当前页码 -->
    <span>Current Page {{ page_obj.number }} of {{ page_obj.paginator.num_pages }} </span>
    
    {% if page_obj.has_next %}
    <a class="navigate pull-right" href="?page={{ page_obj.next_page_number }}">更 多 >>> <i class="fa fa-caret-right"></i></a>
    {% endif %}
</div>

附加：

Paginator常用的属性和方法

count 总共有多少条记录
num_pages 总共有多少页
page_range 页面的区间

Page 常用属性和方法

has_next
has_previous
next_page_number
previous_page_number
number 当前页
start_index 当前页的第一条记录的索引值
end_index 当前页的最后一条记录的索引值

Paginator 练习

(django_exercise_book) [ 22-04-02 11:08 ] [ colinspace ] python manage.py shell
Python 3.9.6 (default, Jul 16 2021, 13:41:17)
[Clang 12.0.5 (clang-1205.0.22.11)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
(InteractiveConsole)
>>> from django.core.paginator import Paginator
>>> obj_list = ['apple', 'orange', 'banana', 'tomato', 'pear' ]
>>> paginator = Paginator(obj_list, 2)
>>> paginator
<django.core.paginator.Paginator object at 0x106cf8130>
>>> paginator.
paginator.ELLIPSIS                paginator.get_page(               paginator.page(
paginator.allow_empty_first_page  paginator.num_pages               paginator.page_range
paginator.count                   paginator.object_list             paginator.per_page
paginator.get_elided_page_range(  paginator.orphans                 paginator.validate_number(
>>> paginator.count
5
>>> paginator.num_pages
3
>>> paginator.per_page
2
>>> paginator.page_range
range(1, 4)
>>> paginator.object_list
['apple', 'orange', 'banana', 'tomato', 'pear']
>>>
>>>
>>> page1 = paginator.page(2)
>>> page2 = paginator.page(2)
>>>
>>> page2
<Page 2 of 3>
>>> page2.
page2.count(                 page2.has_other_pages(       page2.next_page_number(      page2.paginator
page2.end_index(             page2.has_previous(          page2.number                 page2.previous_page_number(
page2.has_next(              page2.index(                 page2.object_list            page2.start_index(
>>> page2.has_previous()
True
>>> page2.has_next()
True
>>> page2.number
2
>>> page2.has_other_pages()
True
>>> page2.next_page_number()
3
>>> page2.previous_page_number()
1
>>> page2.start_index()
3
>>> page2.end_index()
4
>>>

参考：
https://docs.djangoproject.com/en/3.2/topics/pagination/

Django接入Celery实现任务管理

2022-01-30发表Django / Celery10 分钟读完 (大约1562个字)

Django接入Celery实现任务管理，并且启用flower进行任务的可视化查看。另外任务的结果除了保存在Redis中之外，我们也可以选在保存在MySQL等持久化数据库，方便后续做统计分析，结果查询等等操作

django 发布应用

2017-09-19发表Python / Django5 分钟读完 (大约680个字)

Django deploy application

当Django 的application开发完成之后，我们希望能将其作为模块分发出去供别人共享使用

How to write application

安装好Django之后

## create project
django-admin.py startproject mypro

## create app named `todo` (todo list)
cd mypro
python manage.py startapp todo

## configure app(todo) connect with project `mypro`
vim mypro/settings.py

    INSTALLED_APPS = [
        'django.contrib.admin',
         ...,
        'todo',
    ]

vim mypro/urls.py
    from django.conf.urls import url, include

    urlpatterns = [
        url(r'^admin/', admin.site.urls),
        url(r'^todo/', include('todo.urls', namespace='todo')),
    ]

How to write setup.py

创建一个父目录

mkdir -pv /opt/django-todo
copy 刚才新增的 application todo 到该目录下

cp -r todo /opt/django-todo/

一般开发完成application之后，在todo 下面会生成__pycache__ 和 migrations, 一般会保留migrations 作为应用的初始化；或者删除不打包到Python package中，安装应用之后可以使用python manage.py makemigrations todo
和 python manage.py migrate todo 来初始化；
__pycache__ 可以删除不做打包
新增README.MD 和 setup.py

README.MD 作为项目的详细说明，这里省略，详细可以参考：todo README
setup.py 是打包安装脚本，详细脚本如下：

import os
from setuptools import find_packages, setup

with open(os.path.join(os.path.dirname(__file__), 'README.rst')) as readme:
    README = readme.read()

# 使 setup.py 能在任何地方运行
os.chdir(os.path.normpath(os.path.join(os.path.abspath(__file__), os.pardir)))

setup(
    name='colinws-todo',
    version='0.3',
    # packages=find_packages(),
    packages=['todo'],
    include_package_data=True,
    license='MIT License',
    description='A simple Django Todo List application',
    long_description=README,
    url='https://blog.colinspace.com/',
    author='Colin.Liu',
    author_email='colinservice@126.com',
    platforms = 'Linux,Unix',
    keywords = 'Colin,colinws,todo, todo list, django',
    classifiers=[
        'Environment :: Web Environment',
        'Framework :: Django',
        'Framework :: Django :: 1.11',
        'Intended Audience :: Developers',
        'License :: OSI Approved :: MIT License',
        'Operating System :: OS Independent',
        'Programming Language :: Python',
        'Programming Language :: Python :: 3',
        'Programming Language :: Python :: 3.5',
        'Topic :: Internet :: WWW/HTTP',
        'Topic :: Internet :: WWW/HTTP :: Dynamic Content',
    ],
)

编译打包、安装、注册、上传

python setup.py sdist
python setup.py register
python setup.py upload

Python发布package到pypi配置

新增~/.pypirc 而不是 ~/.pypi

刚才报错Server response (410): Project pre-registration is no longer required or supported, so continue dire 就是配置文件命名成了 ~/.pypi

[distutils]
index-servers = pypi

[pypi]
repository: https://upload.pypi.org/legacy/
username: colin5063
password: xxxxxx

第三方安装

you can install via pip

pip install colinws-todo

or you can git clone this repository and use setup.py

git clone https://github.com/opscolin/Django-todo.git
cd Django-todo
python setup.py install

Quick start

Add "todo" to your INSTALLED_APPS setting like this:
```
INSTALLED_APPS = [ ... 'todo',]
```
Include the todo URLconf in your project urls.pylike this:
```
url(r'^todo/', include('todo.urls')),
```
Run below command to create todo models migrations.:
```
python manage.py makemigrations todo
```
Run below command to create todo real models.:
```
python manage.py migrate todo
```
Start the development server and visit http://127.0.0.1:8000/admin/ to create a todo (you’ll need the Admin app enabled).
Visit http://127.0.0.1:8000/todo/ to participate in the todo list.