django-import-export插件使用教程
顾名思义，这是一个用于处理导入和导出数据的库。django-import-export库支持多种格式，包括xls、csv、json、yaml以及tablib支持的所有其他格式。它还有一个Django管理集成，使用起来非常方便。
安装插件
使用PIP安装
pip install django-import-export
更新settings.py:
INSTALLED_APPS = (
...
'import_export',
)
还有一个可选的配置，我通常这样添加:
IMPORT_EXPORT_USE_TRANSACTIONS = True
默认值为False。它确定库是否会在数据导入中使用数据库事务，以确保安全。
Resources
django-import-export库使用Resource的概念，它的类定义非常类似于Django处理模型表单和管理类的方式。
在文档中，作者建议将与资源相关的代码放在admin.py文件。但是，如果实现与Django admin没有关系，我通常更喜欢在app文件夹里创建一个名为resources.py。
models.py
from django.db import models
class Person(models.Model):
name = models.CharField(max_length=30)
email = models.EmailField(blank=True)
birth_date = models.DateField()
location = models.CharField(max_length=100, blank=True)
resources.py
from import_export import resources
from .models import Person
class PersonResource(resources.ModelResource):
class Meta:
model = Person
这是最简单的定义。您可以将几个配置传递给元类，如：fields, exclude
导出数据
导出数据到CSV
from .resources import PersonResource
person_resource = PersonResource()
dataset = person_resource.export()
dataset.csv
id,name,email,birth_date,location
1,John,john@doe.com,2016-08-11,Helsinki
2,Peter,peter@example.com,2016-08-11,Helsinki
3,Maria,maria@gmail.com,2016-08-11,Barcelona
4,Vitor,vitor@freitas.com,2016-08-11,Oulu
5,Erica,erica@gmail.com,2016-08-11,Oulu
导出数据到JSON
dataset.json
[
{"id": 1, "name": "John", "email": "john@doe.com", "birth_date": "2016-08-11", "location": "Helsinki"},
{"id": 2, "name": "Peter", "email": "peter@example.com", "birth_date": "2016-08-11", "location": "Helsinki"},
{"id": 3, "name": "Maria", "email": "maria@gmail.com", "birth_date": "2016-08-11", "location": "Barcelona"},
{"id": 4, "name": "Vitor", "email": "vitor@freitas.com", "birth_date": "2016-08-11", "location": "Oulu"},
{"id": 5, "name": "Erica", "email": "erica@gmail.com", "birth_date": "2016-08-11", "location": "Oulu"}
]
导出数据到YAML
dataset.yaml
- {birth_date: '2016-08-11', email: john@doe.com, id: 1, location: Helsinki, name: John}
- {birth_date: '2016-08-11', email: peter@example.com, id: 2, location: Helsinki, name: Peter}
- {birth_date: '2016-08-11', email: maria@gmail.com, id: 3, location: Barcelona, name: Maria}
- {birth_date: '2016-08-11', email: vitor@freitas.com, id: 4, location: Oulu, name: Vitor}
- {birth_date: '2016-08-11', email: erica@gmail.com, id: 5, location: Oulu, name: Erica}
过滤数据
from .resources import PersonResource
from .models import Person
person_resource = PersonResource()
queryset = Person.objects.filter(location='Helsinki')
dataset = person_resource.export(queryset)
dataset.yaml
- {birth_date: '2016-08-11', email: john@doe.com, id: 1, location: Helsinki, name: John}
- {birth_date: '2016-08-11', email: peter@example.com, id: 2, location: Helsinki, name: Peter}
视图的例子
导出到CSV视图
from django.http import HttpResponse
from .resources import PersonResource
def export(request):
person_resource = PersonResource()
dataset = person_resource.export()
response = HttpResponse(dataset.csv, content_type='text/csv')
response['Content-Disposition'] = 'attachment; filename="persons.csv"'
return response
导出到Excel视图
from django.http import HttpResponse
from .resources import PersonResource
def export(request):
person_resource = PersonResource()
dataset = person_resource.export()
response = HttpResponse(dataset.xls, content_type='application/vnd.ms-excel')
response['Content-Disposition'] = 'attachment; filename="persons.xls"'
return response
导入数据
查看new_persons.csv的数据：
name,email,birth_date,location,id
Jessica,jessica@jones.com,2016-08-11,New York,
Mikko,mikko@suomi.com,2016-08-11,Jyväskyla,
id必须存在，因为它是主键。但是它会生成，所以我们不需要指定值。
import.html
{% extends 'base.html' %}
{% block content %}
<form method="post" enctype="multipart/form-data">
{% csrf_token %}
<input type="file" name="myfile">
<button type="submit">Upload</button>
</form>
{% endblock %}
views.py
from tablib import Dataset
def simple_upload(request):
if request.method == 'POST':
person_resource = PersonResource()
dataset = Dataset()
new_persons = request.FILES['myfile']
imported_data = dataset.load(new_persons.read())
result = person_resource.import_data(dataset, dry_run=True) # Test the data import
if not result.has_errors():
person_resource.import_data(dataset, dry_run=False) # Actually import now
return render(request, 'core/simple_upload.html')
Django后台管理
在admin.py里使用ImportExportModelAdmin，而不是ModelAdmin
from import_export.admin import ImportExportModelAdmin
from django.contrib import admin
from .models import Person
@admin.register(Person)
class PersonAdmin(ImportExportModelAdmin):
pass
添加之后刷新页面你就会看到导入和导出按钮。
在导入现有项目时，导入功能具有良好的差异性：
这是一个大的Django库。你可以用它做更多的事情。它的文档完全值得一看：API reference.
