django学习(一)

一、安装django

1、下载django：http://www.djangoproject.com/download/（我安装的版本：Django-1.0.2-final）

2、解压后在在命令行执行 python setup.py install，安装过程中会将文件copy到 D:\Python25\Lib\site-packages下。

3、修改path环境变量，追加D:\Python25\Scripts。

4、验证是否安装成功，随便找一个文件夹在命令行执行django-admin.py startproject leesite,如果成功创建文件夹sitename，django安装成功！

leesite下有四个文件：　
__init__.py

表示这是一个 Python 的包
manage.py: 提供简单化的 django-admin.py 命令，特别是可以自动进行 DJANGO_SETTINGS_MODULES 和 PYTHONPATH 的处理，而没有这个命令，处理上面环境变量是件麻烦的事情
settings.py: 它是django的配置文件
uls.py: url映射处理文件， Karrigell 没有这种机制，它通过目录/文件/方法来自动对应，而 Django 的url映射是url对于某个模块方法的映射，目前不能自动完成

注意点：

1》django-admin.py,请注意不是下划线。

二、Hello django！

1、启动webserver

启动：E:\liyp\django\leesite>manage.py runserver

浏览：http://localhost:8000/，Welcome to Django！

2、在E:\liyp\django\leesite>下新建一个helloworld.py文件。

Code
from django.http import HttpResponse

def index(request):
return HttpResponse("Hello, Django.")

3、修改urls.py

Code
from django.conf.urls.defaults import *

# Uncomment the next two lines to enable the admin:
# from django.contrib import admin
# admin.autodiscover()

urlpatterns = patterns('',
    # Example:
    # (r'^leesite/', include('leesite.foo.urls')),
   (r'^$', 'leesite.helloworld.index'),
    # Uncomment the admin/doc line below and add 'django.contrib.admindocs'
    # to INSTALLED_APPS to enable admin documentation:
    # (r'^admin/doc/', include('django.contrib.admindocs.urls')),

    # Uncomment the next line to enable the admin:
    # (r'^admin/(.*)', admin.site.root),
)

三、实现一个加法功能

1、在E:\liyp\django\leesite>下新建一个add.py文件。

Code
from django.http import HttpResponse

text="""<form method="post" action="/add/">
        <input type="text" name="a" value="%d">
        +
        <input type="text" name="b" value="%d">
        <input type="submit" value="=">
        <input type="text" value="%d">
        </form>"""

def index(request):
    if request.POST.has_key('a'):
        a=int(request.POST['a'])
        b=int(request.POST['b'])
    else:
        a=0
        b=0
    return HttpResponse(text%(a,b,a+b))

3、修改urls.py

Code
from django.conf.urls.defaults import *

# Uncomment the next two lines to enable the admin:
# from django.contrib import admin
# admin.autodiscover()

urlpatterns = patterns('',
    # Example:
    # (r'^leesite/', include('leesite.foo.urls')),
   (r'^$', 'leesite.helloworld.index'),
    (r'^add/$','leesite.add.index'),
    # Uncomment the admin/doc line below and add 'django.contrib.admindocs'
    # to INSTALLED_APPS to enable admin documentation:
    # (r'^admin/doc/', include('django.contrib.admindocs.urls')),

    # Uncomment the next line to enable the admin:
    # (r'^admin/(.*)', admin.site.root),
)

注意点：

1、 action 为 /add/，在 Django 中链接后面一般都要有 '/' ，不然有可能得不到 POST 数据。
2、 method="post"，表示要对数据进行修改，GET 表示获取数据。
3、浏览http://localhost:8000/add/查看效果。

四、使用模板

1、创建list.py

Code
#coding=utf-8
from django.shortcuts import render_to_response

address = [
    {'name':'张三', 'address':'地址一'},
    {'name':'李四', 'address':'地址二'}
    ]

def index(request):
    return render_to_response('list.html', {'address': address})

    注意：
       1、使用汉字时采用utf-8编码。
       2、address为一个list，每个list为一个字典。
2、创建模板
      1、新建模板文件夹：E:\liyp\django\leesite\templates
      2、设置模板路径：修改settings.py

Code

TEMPLATE_DIRS = (
    # Put strings here, like "/home/html/django_templates" or "C:/www/django/templates".
    # Always use forward slashes, even on Windows.
    # Don't forget to use absolute paths, not relative paths.
    './templates',
)

3、建立模板文件 E:\liyp\django\leesite\templates\list.html

Code
<h2>通讯录</h2>
<table border="1">
  <tr><th>姓名</th><th>地址</th></tr>
  {% for user in address %}
  <tr>
  <td>{{ user.name }}</td>
  <td>{{ user.address }}</td>
  </tr>
{% endfor %}
</table>

注意：
1、文件格式为utf-8
4、修改访问路径 urls.py(http://localhost:8000/list/)

Code
from django.conf.urls.defaults import *

# Uncomment the next two lines to enable the admin:
# from django.contrib import admin
# admin.autodiscover()

urlpatterns = patterns('',
    # Example:
    # (r'^leesite/', include('leesite.foo.urls')),
    (r'^$', 'leesite.helloworld.index'),
    (r'^add/$','leesite.add.index'),
    (r'^list/$','leesite.list.index'),
    # Uncomment the admin/doc line below and add 'django.contrib.admindocs'
    # to INSTALLED_APPS to enable admin documentation:
    # (r'^admin/doc/', include('django.contrib.admindocs.urls')),

    # Uncomment the next line to enable the admin:
    # (r'^admin/(.*)', admin.site.root),
)

五、生成并下载CSV格式文件
1、创建csv_test.py

Code
#coding=utf-8
from django.http import HttpResponse
from django.template import loader, Context

address = [
    ('张三', '地址一'),
    ('李四', '地址二')
    ]

def output(request, filename):
    response = HttpResponse(mimetype='text/csv')
    response['Content-Disposition'] = 'attachment; filename=%s.csv' % filename

    t = loader.get_template('csv.html')
    c = Context({
        'data': address,
    })
    response.write(t.render(c))
    return response

2、添加模板 E:\liyp\django\leesite\templates\csv.html

Code
{% for row in data %}"{{ row.0|addslashes}}", "{{ row.1|addslashes}}",
{% endfor %}

3、修改urls.py(http://localhost:8000/csv/address)

Code
from django.conf.urls.defaults import *

# Uncomment the next two lines to enable the admin:
# from django.contrib import admin
# admin.autodiscover()

urlpatterns = patterns('',
    # Example:
    # (r'^leesite/', include('leesite.foo.urls')),
    (r'^$', 'leesite.helloworld.index'),
    (r'^add/$','leesite.add.index'),
    (r'^list/$','leesite.list.index'),
    (r'^csv/(?P<filename>\w+)/$', 'leesite.csv_test.output'),
    # Uncomment the admin/doc line below and add 'django.contrib.admindocs'
    # to INSTALLED_APPS to enable admin documentation:
    # (r'^admin/doc/', include('django.contrib.admindocs.urls')),

    # Uncomment the next line to enable the admin:
    # (r'^admin/(.*)', admin.site.root),
)

六、session
1、创建logon.py

Code
from django.http import HttpResponseRedirect
from django.shortcuts import render_to_response

def login(request):
    username = request.POST.get('username', None)
    if username:
        request.session['username'] = username
    username = request.session.get('username', None)
    if username:
        return render_to_response('login.html', {'username':username})
    else:
        return render_to_response('login.html')

def logout(request):
    try:
        del request.session['username']
    except KeyError:
        pass
    return HttpResponseRedirect("/login/")

2、创建模板 E:\liyp\django\leesite\templates\login.html

Code
{% if not username %}
<form method="post" action="/login/">
    用户名：<input type="text" name="username" value=""><br/>
    <input type="submit" value="登录">
</form>
{% else %}
你已经登录了！{{ username }}<br/>
<form method="post" action="/logout/">
    <input type="submit" value="注销">
</form>
{% endif %}

3、修改urls.py(http://localhost:8000/login)

Code
from django.conf.urls.defaults import *

# Uncomment the next two lines to enable the admin:
# from django.contrib import admin
# admin.autodiscover()

urlpatterns = patterns('',
    # Example:
    # (r'^leesite/', include('leesite.foo.urls')),
    (r'^$', 'leesite.helloworld.index'),
    (r'^add/$','leesite.add.index'),
    (r'^list/$','leesite.list.index'),
    (r'^csv/(?P<filename>\w+)/$', 'leesite.csv_test.output'),
    (r'^login/$', 'leesite.login.login'),
    (r'^logout/$', 'leesite.login.logout'),

    # Uncomment the admin/doc line below and add 'django.contrib.admindocs'
    # to INSTALLED_APPS to enable admin documentation:
    # (r'^admin/doc/', include('django.contrib.admindocs.urls')),

    # Uncomment the next line to enable the admin:
    # (r'^admin/(.*)', admin.site.root),
)

4、配置数据库 django中的session是保存在数据库中的，在settings.py中设置数据库

Code
DATABASE_ENGINE = 'sqlite3'
DATABASE_NAME = './data.db'
DATABASE_USER = ''
DATABASE_PASSWORD = ''
DATABASE_HOST = ''
DATABASE_PORT = ''

sqlite是一个轻量级的数据库，类似于Access，但是没有像Access一样提供丰富的界面组件。从python 2.5开始，python提供了对sqlite3的内生支持，
在PythonDir\Dlls\下可以看到 sqlite3.dll和_sqlite3.pyd ，这2个文件是python支持sqlite3的基础；
5、建库、建表
manage.py syncdb

在E:\liyp\django\leesite下会多出一个data.db文件。
参考：

http://www.woodpecker.org.cn/obp/django/django-stepbystep/newtest/doc/