list()在谷歌应用引擎中不起作用?

我正在尝试使用App Engine中的set函数,准备一个包含唯一元素的列表。我在编写Python代码时遇到了一个问题,该代码在Python Shell中运行良好,但在App Engine+Django中运行不佳

import re
value='   r.dushaynth@gmail.com, dash@ben,,  , abc@ac.com.edu    '
value = value.lower()
value = list(set(re.split('^\s*|\s*,+\s*|\s*$', value)))
if (value[0] == ''):
    value.remove('')
print value       

['dash@ben', 'abc@ac.com.edu', 'r.dushaynth@gmail.com']

现在,当我在App Engine的views.py文件中执行等效操作时:

import os
import re
import django
from django.http import HttpResponse
from django.shortcuts import render_to_response # host of other imports also there
def add(request):

    value='   r.dushaynth@gmail.com, dash@ben,,  , abc@ac.com.edu    '
    value = value.lower()
    value = list(set(re.split('^\s*|\s*,+\s*|\s*$', value)))
    if (value[0] == ''):
        value.remove('')


    return render_to_response('sc-actonform.html', {
        'value': value,
    })

我在转到相应页面(粘贴回溯)时遇到此错误:

Traceback (most recent call last):
File "G:\Dhushyanth\Google\google_appengine\lib\django\django\core\handlers\base.py" in get_response
  77. response = callback(request, *callback_args, **callback_kwargs)
File "G:\Dhushyanth\development\AppengineProjects\trunk_sanjhachoolha\sandbox\dushyanth\sanjhachoolha\views.py" in add
  148. value = list(set(re.split('^\s*|\s*,+\s*|\s*$', value)))
File "G:\Dhushyanth\development\AppengineProjects\trunk_sanjhachoolha\sandbox\dushyanth\sanjhachoolha\views.py" in list
  208. return respond(request, None, 'sc-base', {'content': responseText})
File "G:\Dhushyanth\development\AppengineProjects\trunk_sanjhachoolha\sandbox\dushyanth\sanjhachoolha\views.py" in respond
  115. params['sign_in'] = users.create_login_url(request.path)

  AttributeError at /sanjhachoolha/acton/add
  'set' object has no attribute 'path'

评论出来:

#value = list(set(re.split('^\s*|\s*,+\s*|\s*$', value)))

我在相应的网页上得到了所需的输出:

r.dushaynth@gmail.com, dash@ben,, , abc@ac.com.edu

谢谢!