Django Admin中增加导出CSV功能过程解析

.......
@admin.register(Issue)
class IssueAdmin(admin.ModelAdmin):
  ......
  actions = ['export_as_csv'] # 增加动作, 对应相应的方法名
  def export_as_csv(self, request, queryset): # 具体的导出csv方法的实现
    pass
  export_as_csv.short_description = '导出CSV' # 该动作在admin中的显示文字

  def export_as_csv(self, request, queryset):
    meta = self.model._meta # 用于确定导出的文件名, 格式为: app名.模型类名
    field_names = [field.name for field in meta.fields] # 所有属性名

    response = HttpResponse(content_type='text/csv')  # 指定响应内容类型
    response['Content-Disposition'] = f'attachment; filename={meta}.csv'
    response.charset = 'utf-8-sig' # 可选, 修改编码为带BOM的utf-8格式(Excel打开不会有乱码)
    writer = csv.writer(response)
    writer.writerow(field_names) # 将属性名写入csv
    for obj in queryset: # 遍历要导出的对象列表
      row = writer.writerow([getattr(obj, field) for field in field_names]) # 将当前对象的各属性值写入csv
    return response

import csv
from django.contrib import admin
from django.http import HttpResponse
from .models import Issue
class ExportCsvMixin(object):
  def export_as_csv(self, request, queryset):
    meta = self.model._meta
    field_names = [field.name for field in meta.fields]
    response = HttpResponse(content_type='text/csv')
    response['Content-Disposition'] = f'attachment; filename={meta}.csv'
    response.charset = 'utf-8-sig'
    writer = csv.writer(response)
    writer.writerow(field_names)
    for obj in queryset:
      row = writer.writerow([getattr(obj, field) for field in field_names])
    return response
  export_as_csv.short_description = '导出CSV'
@admin.register(Issue)
class IssueAdmin(admin.ModelAdmin, ExportCsvMixin):
  fields = ('key', 'summary', 'status', 'project',
       'origin', 'components', 'prj_level', 'prj_category',
       'assignee', 'origin_person', 'pm', 'dev_manager', 'test_manager', 'tester', 'fe_dev', 'backend_dev',
       'plan_begin', 'plan_end', 'fe_plan_begin', 'fe_plan_end', 'test_plan_begin',
       'test_plan_end', 'backend_plan_begin', 'backend_plan_end',
       'created', 'reopen', 'prd_begin', 'prd_end', 'dev_begin', 'dev_end',
       'test_begin', 'test_end', 'pm_check', 'ready', 'pause', 'done',
       'pm_take', 'dev_take', 'test_take', 'total_take',
       'tags',
       )
  readonly_fields = fields
  list_display = ('key', 'summary', 'status', 'origin', 'components', 'created', 'visit')
  list_filter = ('origin', 'components', 'status', 'tags')
  search_fields = ('key', 'summary')
  date_hierarchy = 'created'
  actions = ['export_as_csv']