如何将起始序列号传递给Django factory_boy工厂？

Question

factory_boy默认1为序列。如何传递数字以用作其他起始号码？我可以对_setup_next_sequence()方法进行子类化，但是如何给它使用一个变量呢？

# File: models.py
from django.db import models

class Book(models.Model):
    title = models.CharField(max_length=100)

# File: factories.py
from .models import Book
import factory

class BookFactory(factory.Factory):
  FACTORY_FOR = BookModel  
  title = factory.Sequence(lambda n: u'Title #{}'.format(n))

  @classmethod
  def _setup_next_sequence(cls):      
      # Instead of defaulting to starting with number 1, start with starting_seq_num.
      # But how do I set starting_seq_num?
      return starting_seq_num

# File: make_data.py
from factories import BookFactory

# somehow set starting sequence number here?

BookFactory().create()

我正在使用factory_boy 1.2.0（via pip install factory_boy）
factory_boy代码：https : //github.com/dnerdy/factory_boy

Answer 1

我找到了两种解决这个问题的方法：

1. 使用模块变量
2. 使用类定义之外的类属性集

使用模块变量：

# File: factories.py
from .models import Book
import factory

starting_seq_num = 0

class BookFactory(factory.Factory):
  FACTORY_FOR = BookModel  
  title = factory.Sequence(lambda n: u'Title #{}'.format(n))

  @classmethod
  def _setup_next_sequence(cls):      
      # Instead of defaulting to starting with 0, start with starting_seq_num.
      return starting_seq_num

# File: make_data.py
import factories

factories.starting_seq_num = 100    
factories.BookFactory().create()

在类定义之外使用类属性集：

# File: factories.py
from .models import Book
import factory

class BookFactory(factory.Factory):
  # Note that starting_seq_num cannot be set here in the class definition,
  # because Factory will then pass it as a kwarg to the model's create() method
  # and cause an exception.  It must be set outside the class definition.
  FACTORY_FOR = BookModel  
  title = factory.Sequence(lambda n: u'Title #{}'.format(n))

  @classmethod
  def _setup_next_sequence(cls):      
      return getattr(cls, 'starting_seq_num', 0)

# File: make_data.py
from factories import BookFactory

BookFactory.starting_seq_num = 100
BookFactory().create()

Answer 2

除了Rob Bednark的答案

我们可以使用reset_sequence()函数，它将计数器重置为特定值。

# File: make_data.py
import factories

factories.BookFactory.reset_sequence(100)
my_book = factories.BookFactory().create()
print(my_book.title) # Title #100

Answer 3

更新：factory_boy现在处理它！

在factory_boy(2.8.1至今)的最新版本中，现在可以将序列计数器强制为定义值：

在每次调用的基础上强制值

为了强制计数器进行特定的Factory实例化，只需在__sequence=42参数中传递值 ：

class AccountFactory(factory.Factory):
        class Meta:
            model = Account
        uid = factory.Sequence(lambda n: n)
        name = "Test"

然后在控制台中：

>>> obj1 = AccountFactory(name="John Doe", __sequence=10)
>>> obj1.uid  # Taken from the __sequence counter
10
>>> obj2 = AccountFactory(name="Jane Doe")
>>> obj2.uid  # The base sequence counter hasn't changed
1

也可以将计数器重置为特定值：

>>> AccountFactory.reset_sequence(42)
>>> AccountFactory().uid
42
>>> AccountFactory().uid
43