给定一个类:
from django.db import models class Person(models.Model): name = models.CharField(max_length=20)
是否有可能,如果有的话,如何拥有一个基于动态参数进行过滤的 QuerySet?例如:
# Instead of: Person.objects.filter(name__startswith='B') # ... and: Person.objects.filter(name__endswith='B') # ... is there some way, given: filter_by = '{0}__{1}'.format('name', 'startswith') filter_value = 'B' # ... that you can run the equivalent of this? Person.objects.filter(filter_by=filter_value) # ... which will throw an exception, since `filter_by` is not # an attribute of `Person`.
Python的参数扩展可以用来解决这个问题:
kwargs = { '{0}__{1}'.format('name', 'startswith'): 'A', '{0}__{1}'.format('name', 'endswith'): 'Z' } Person.objects.filter(**kwargs)
这是一个非常常见和有用的 Python 习惯用法。