如果你在 Django 中搜索字段(例如 IntergField)的参数,则通过
from django.db import models
dir(models.IntegerField)
你会得到"default_error_messages"、"default_validators"、"唯一"、"验证"、"验证器"等,但不是"默认"本身,尽管它是常用的,如
class Choice(models.Model):
...
votes = models.IntegerField(default=0)
与"客户端"相同。文档说TestCase"带有自己的客户端"。在 Django 文档中的这个片段中,探索了这个客户端
class QuestionIndexViewTests(TestCase):
def test_no_questions(self):
"""
If no questions exist, an appropriate message is displayed.
"""
response = self.client.get(reverse('polls:index'))
但你无法通过
from django.test import TestCase
dir(django.test.TestCase)
甚至
dir(django.test.TestCase.client_class)
我问它们来自哪里,以及如何搜索这些"隐藏"的参数、方法等。
.default
不是类的属性,而是实例的属性。事实上,如果我们看一下源代码[GitHub],我们会看到:
class Field(RegisterLookupMixin): # … def __init__(self, verbose_name=None, name=None, primary_key=False, max_length=None, unique=False, blank=False, null=False, db_index=False, rel=None, default=NOT_PROVIDED, editable=True, serialize=True, unique_for_date=None, unique_for_month=None, unique_for_year=None, choices=None, help_text='', db_column=None, db_tablespace=None, auto_created=False, validators=(), error_messages=None): # … self.default = default # …
因此,如果您构造一个IntegerField
对象,则可以找到以下内容:
>>> from django.db.models import IntegerField
>>> dir(IntegerField())
['__class__', '__copy__', '__deepcopy__', '__delattr__', '__dict__', '__dir__', '__doc__', '__eq__', '__format__', '__ge__', '__getattribute__', '__gt__', '__hash__', '__init__', '__init_subclass__', '__le__', '__lt__', '__module__', '__ne__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__sizeof__', '__str__', '__subclasshook__', '__weakref__', '_check_backend_specific_checks', '_check_choices', '_check_db_index', '_check_deprecation_details', '_check_field_name', '_check_max_length_warning', '_check_null_allowed_for_primary_keys', '_check_validators', '_choices_is_value', '_clear_cached_lookups', '_db_tablespace', '_description', '_error_messages', '_get_default', '_get_flatchoices', '_get_lookup', '_unique', '_unregister_lookup', '_validators', '_verbose_name', 'auto_created', 'auto_creation_counter', 'blank', 'cached_col', 'cast_db_type', 'check', 'choices', 'class_lookups', 'clean', 'clone', 'contribute_to_class', 'creation_counter', 'db_check', 'db_column', 'db_index', 'db_parameters', 'db_returning', 'db_tablespace', 'db_type', 'db_type_parameters', 'db_type_suffix', 'deconstruct','default', 'default_error_messages', 'default_validators', 'description', 'descriptor_class', 'editable', 'empty_strings_allowed', 'empty_values', 'error_messages', 'flatchoices', 'formfield', 'get_attname', 'get_attname_column', 'get_choices', 'get_col', 'get_db_converters', 'get_db_prep_save', 'get_db_prep_value', 'get_default', 'get_filter_kwargs_for_object', 'get_internal_type', 'get_lookup', 'get_lookups', 'get_pk_value_on_save', 'get_prep_value', 'get_transform', 'has_default', 'help_text', 'hidden', 'is_relation', 'many_to_many', 'many_to_one', 'max_length', 'merge_dicts', 'name', 'null', 'one_to_many', 'one_to_one', 'pre_save', 'primary_key', 'register_lookup', 'rel_db_type', 'related_model', 'remote_field', 'run_validators', 'save_form_data', 'select_format', 'serialize', 'set_attributes_from_name', 'system_check_deprecated_details', 'system_check_removed_details', 'to_python', 'unique', 'unique_for_date', 'unique_for_month', 'unique_for_year', 'validate', 'validators', 'value_from_object', 'value_to_string', 'verbose_name']
此处可见.default
属性。
对于TestCase
,这是由SimpleTestCase
中实现的逻辑处理的。这将在它运行测试用例时设置测试用例,这包括使用.client
填充对象,该是client_class
类属性引用的类的实例
class SimpleTestCase(unittest.TestCase):
# …
client_class = Client
def __call__(self, result=None):
"""
Wrapper around default __call__ method to perform common Django test
set up. This means that user-defined Test Cases aren't required to
include a call to super().setUp().
"""
self._setup_and_call(result)
def _setup_and_call(self, result, debug=False):
# …
self._pre_setup()
# …
def _pre_setup(self):
# …
self.client = self.client_class()
# …
class TransactionTestCase(SimpleTestCase):
# …
TestCase(TransactionTestCase):
# …
这种情况并不少见。在Python中,属性通常是在对象上定义的,甚至在以后运行测试用例时通过某种方法定义。您只能通过阅读文档来了解这一点。