Django Cheatsheet

django的常用程序片断。

FileResponse / FileField 的相关处理

• 把一个文件存入FileField

  下面的result_file是FieldField类型

  def do_unique(self, req, qs):
      """文件去重"""
      if qs.count() != 1:
          self.message_user(req, '必须且仅可选择一个文件进行比较。', ERROR)
      else:
          obj: m.Upload = qs.first()
          result_file, total, result, diff = yd.biz.do_it_all(obj.db_file.path)
          from django.core.files import File
  
          result_file_name = os.path.basename(result_file)
          obj.result_file.save(result_file_name, File(open(result_file)), save=False)
          obj.status = '完成'
          obj.msg = f'原 {total} 条，去重后 {result} 条，删除 {diff} 条'
          obj.save()
          self.message_user(req, obj.msg, messages.SUCCESS)

• 把media_root目录下的某个文件存入FileField

  def do_unique(self, req, qs):
      """文件去重"""
      if qs.count() != 1:
          self.message_user(req, '必须且仅可选择一个文件进行比较。', ERROR)
      else:
          obj: m.Upload = qs.first()
          result_file, total, result, diff = yd.biz.do_it_all(obj.db_file.path)
          relative_path = os.path.relpath(result_file, settings.MEDIA_ROOT)
          obj.result_file.name = relative_path
          obj.status = '完成'
          obj.msg = f'原 {total} 条，去重后 {result} 条，删除 {diff} 条'
          obj.save()
          self.message_user(req, obj.msg, messages.SUCCESS)

• 把一个字符串存入FileField

  result_file_name = os.path.basename(obj.compare_file.name + '.compare.csv')
  from django.core.files.base import ContentFile
  obj.result_file.save(result_file_name, ContentFile(result), save=False)
  obj.status = '完成'
  obj.save()
  self.message_user(req, '处理完成', messages.SUCCESS)

django admin action 请用户提供信息

http://tech.willandskill.se/custom-django-admin-2/

把celery worker作成服务

http://docs.celeryproject.org/en/latest/userguide/daemonizing.html

• celery配置文件

  mkdir /etc/conf.d
  vi /etc/conf.d/celery

  # Name of nodes to start
  # here we have a single node
  CELERYD_NODES="w1"
  # or we could have three nodes:
  #CELERYD_NODES="w1 w2 w3"
  
  # Absolute or relative path to the 'celery' command:
  CELERY_BIN="/home/pi/.local/share/virtualenvs/iot1-Ffl3idFE/bin/celery"
  #CELERY_BIN="/virtualenvs/def/bin/celery"
  
  # App instance to use
  # comment out this line if you don't use an app
  # config.celery包应该存在
  CELERY_APP="config"
  # or fully qualified:
  #CELERY_APP="proj.tasks:app"
  
  # How to call manage.py
  CELERYD_MULTI="multi"
  
  # Extra command-line arguments to the worker
  CELERYD_OPTS="--time-limit=300 --concurrency=4"
  
  # - %n will be replaced with the first part of the nodename.
  # - %I will be replaced with the current child process index
  #   and is important when using the prefork pool to avoid race conditions.
  CELERYD_PID_FILE="/home/pi/src/iot1/logs/celery-worker-%n.pid"
  CELERYD_LOG_FILE="/home/pi/src/iot1/logs/celery-worker-%n%I.log"
  CELERYD_LOG_LEVEL="INFO"

• celery 启动脚本

  vi /etc/systemd/system/celery.service

这个地方没有要修改的。

[Unit]
Description=Celery Service
After=network.target

[Service]
Type=forking
User=celery
Group=celery
EnvironmentFile=/etc/conf.d/celery
WorkingDirectory=/opt/celery
ExecStart=/bin/sh -c '${CELERY_BIN} multi start ${CELERYD_NODES} \
  -A ${CELERY_APP} --pidfile=${CELERYD_PID_FILE} \
  --logfile=${CELERYD_LOG_FILE} --loglevel=${CELERYD_LOG_LEVEL} ${CELERYD_OPTS}'
ExecStop=/bin/sh -c '${CELERY_BIN} multi stopwait ${CELERYD_NODES} \
  --pidfile=${CELERYD_PID_FILE}'
ExecReload=/bin/sh -c '${CELERY_BIN} multi restart ${CELERYD_NODES} \
  -A ${CELERY_APP} --pidfile=${CELERYD_PID_FILE} \
  --logfile=${CELERYD_LOG_FILE} --loglevel=${CELERYD_LOG_LEVEL} ${CELERYD_OPTS}'

[Install]
WantedBy=multi-user.target

• 最后再启动下，就ok了

  systemctl enable celery
  systemctl start celery

独立使用django

# 独立使用django
import os
os.environ['DJANGO_SETTINGS_MODULE'] = 'config.settings'
import django
django.setup()

django中混用vue/jquery

直接上代码。

• admin.py

  @admin.register(m.Light)
  class LightAdmin(admin.ModelAdmin):
  class Media:
      css = {
          "all": (
              # "//cdn.bootcss.com/pure/1.0.0/pure-min.css",
              "iot1/lightadmin.css",
          )
      }
      js = (
          "//cdn.bootcss.com/vue/2.5.17-beta.0/vue.min.js",
          "//cdn.bootcss.com/jquery/1.12.4/jquery.js",
          "iot1/lightadmin.js",
          "//cdn.bootcss.com/layer/2.3/layer.js",
          # 这个require要放在最后。要不会卡住，其它js不运行了
          "//cdn.bootcss.com/require.js/2.3.6/require.min.js",
      )
  list_display = ('id', 'code', 'counter', 'status', 'power', 'voltage', 'last_measure_on', 'field_operation')
  
  def field_operation(self, obj):
      # return '播放'
      html = """        
         <button class="button-xsmall pure-button" @click="viewLocations({obj.id})" type="button">位置</button>
         """.format(obj=obj)
      return mark_safe(html)

• iot1/lightadmin.js

  window.onload = function () {
  var app = new Vue({
  el: '#container',
  data: {
    msg: 'Hello Vue!'
  },
  created: function () {
    // 再运行一次actions，因为vue会把一些dom结构破坏掉。再运行一次，以便django的功能恢复
    require(["/static/admin/js/actions.js"])
  },
  methods: {
    viewLocations(id) {
      alert(id)
    }
  }
  })
  }