python编程

   我是刚刚学习Django,所以在学习中遇到了一些问题，希望我的分享对大家有一点用处。
1.安装python2.5.x.
2.安装MySQL.
3.安装MySQL-python-1.2.2.win32-py2.5.exe。
4.想必大家在生成mysite的时候没有什么问题吧，mysite下面的settings.py中mysql数据库的配置如下：
    DATABASES = {
    'default': {
       'ENGINE': 'django.db.backends.mysql',
       'NAME': 'MySQL',        
       'USER': 'root',                            
       'PASSWORD': '123456',                 
       'HOST': '',        
       'PORT': '3306',                         }
}
配置完后，测试一下数据库吧。
记得把MySQL数据库打开。
转到创建的mysite 项目目录，运行 python manage.py shell 命令

>>> from django.db import connection
>>> cursor = connection.cursor()

转到mysite 项目目录，执行下面的命令来创建一个新app叫做books：
python manage.py startapp books


from django.db import models
class Publisher(models.Model):
    name = models.CharField(maxlength=30)
    address = models.CharField(maxlength=50)
    city = models.CharField(maxlength=60)
    state_province = models.CharField(maxlength=30)
    country = models.CharField(maxlength=50)
    website = models.URLField()
class Author(models.Model):
    salutation = models.CharField(maxlength=10)
    first_name = models.CharField(maxlength=30)
    last_name = models.CharField(maxlength=40)
    email = models.EmailField()
    headshot = models.ImageField(upload_to='/tmp')
class Book(models.Model):
    title = models.CharField(maxlength=100)
    authors = models.ManyToManyField(Author)
    publisher = models.ForeignKey(Publisher)
    publication_date = models.DateField()

需要把变量maxlength改为max_length要不然会出现错误，如下：
File "D:\installFiles\python252\Lib\site-packages\django\utils\importlib.py",
line 35, in import_module
   __import__(name)
File "D:\installFiles\python252\Lib\site-packages\django\bin\mysite\..\mysite\
books\models.py", line 2, in <module>
   class Publisher(models.Model):
File "D:\installFiles\python252\Lib\site-packages\django\bin\mysite\..\mysite\
books\models.py", line 3, in Publisher
   name = models.CharField(maxlength=30)


File "D:\installFiles\python252\Lib\site-packages\django\db\models\fields\__in
it__.py", line 545, in __init__
   super(CharField, self).__init__(*args, **kwargs)
TypeError: __init__() got an unexpected keyword argument 'maxlength'


def __init__(self, *args, **kwargs):
        super(CharField, self).__init__(*args, **kwargs)
        self.validators.append(validators.MaxLengthValidator(self.max_length))

在fields\__init__.py的line545定义的变量为max_length,而不是maxlength,所以需要把maxlength改为max_length就OK了，现在运行python manage.py validate就没有问题了。