CharField()类的参数 [英] Parameters for class CharField()
问题描述
CharField('name',max_length = 100)
和 CharField(max_length = 100)
有什么区别?
参数名称"
的用途是什么?
什么是 CharField()
构造函数?
What is the difference between CharField('name',max_length=100)
and CharField(max_length=100)
?
What is the parameter 'name'
used for?
What are the CharField()
constructors?
有人可以给我链接吗?
推荐答案
CharField继承自名为Field的类,该类具有构造函数
CharField inherits from class called Field which has constructor
class Field(RegisterLookupMixin):
"""Base class for all field types"""
# <some more code>
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):
Char字段构造器
class CharField(Field):
description = _("String (up to %(max_length)s)")
def __init__(self, *args, **kwargs):
super(CharField, self).__init__(*args, **kwargs)
self.validators.append(validators.MaxLengthValidator(self.max_length))
charfield构造函数基本上将参数(关键字和普通)传递给字段构造函数,并添加一个maxlength验证器.
The charfield constructor basically passes arguments (keyword and ordinary) to field constructor and adds a maxlength validator.
因此CharField('name',max_length = 100的参数'name'被分配给verbose_name
So the argument 'name' in CharField('name',max_length=100 gets assigned to verbose_name
查看此
https://github.com/django/django/blob/master/django/db/models/fields/__ init__.py
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