无法将文本文件上传到django项目

我使用的是Ubuntu 14.04，Apache2和mod_wsgi-4.5.3，Django 1.10b1，我是wsgi的新手 . 每当我尝试将txt文件上传到我的网站时，我在mod_wsgi错误日志中收到以下错误：[Thu Jul 07 19：39：20.261989 2016] [wsgi：error] [pid 1233：tid 140054790215424] txt

该网页显示“服务器错误500”

这是我的wsgi.py

import os
import sys
import site

# Add the site-packages of the chosen virtualenv to work with
site.addsitedir('/home/django/myvirtualenvironment/lib/python3.4/site-packages')

# Add the app's directory to the PYTHONPATH
sys.path.append('/home/django/myvirtualenvironment/DoTanalyzer')
sys.path.append('/home/django/myvirtualenvironment/DoTanalyzer/TextAnalyzer')

os.environ['DJANGO_SETTINGS_MODULE'] = 'TextAnalyzer.settings'

# Activate your virtual env
activate_env=os.path.expanduser("/home/django/myvirtualenvironment/bin/activate_this.py")
# execfile(activate_env, dict(__file__=activate_env))
exec(compile(open(activate_env, "rb").read(), activate_env, 'exec'), dict(__file__activate_env))

import django.core.handlers.wsgi
# Add the app's directory to the PYTHONPATH
sys.path.append('/home/django/myvirtualenvironment/DoTanalyzer')
sys.path.append('/home/django/myvirtualenvironment/DoTanalyzer/TextAnalyzer')

os.environ['DJANGO_SETTINGS_MODULE'] = 'TextAnalyzer.settings'

import django.core.handlers.wsgi
application = django.core.handlers.wsgi.WSGIHandler()

from django.core.wsgi import get_wsgi_application
application = get_wsgi_application()

这是我在views.py中保存文件的方法

def upload_file(request):
    if not request.user.is_authenticated():
        return render(request, 'analyze/login_user.html')
    else:
        form = FileForm(request.POST or None, request.FILES or None)
        if form.is_valid():
            file = form.save(commit=False)
            file.user = request.user
            file.file = request.FILES['file']
            file.file_name = request.FILES['file'].name
            file_type = file.file.url.split('.')[-1]
            print(file_type)
            if check_file_type(file_type):
                file.save()
                return render(request, 'analyze/results.html', {'results': results})
            else:
                return render(request, 'analyze/upload_file.html', {'form': form, 'error_message': '.txt only'})
        else:
            return render(request, 'analyze/upload_file.html', {'form': form})