小编ram*_*mar的帖子

我有这样一个数组:

arr = []
arr[0] = "ab"
arr[1] = "abcdefgh"
arr[2] = "abcd"

排序后,输出数组应为:

arr[0] = "abcdefgh"
arr[1] = "abcd"
arr[2] = "ab"  

我的意思是,我希望按每个元素长度的降序排列.

我在Windows上使用python django,并尝试部署到heroku.当我尝试使用pip安装psycopg2时,

     pip install psycopg2 

我得到错误:
无法找到vcvarsall.bat
然后我发现我需要安装visual studio 2008(或)我可以直接下载并安装编译版本,所以从这个链接下载:
http://www.lfd.uci.edu / ~gohlke/pythonlibs /
我下载的文件名:psycopg2-2.4.5.win32-py2.7.exe
即使安装完成后我也收到错误:没有名为psycopg2.extensions的模块

那么,我还应该做些什么呢？

            D:\mycode\python\mysite>heroku run python manage.py syncdb
            Running python manage.py syncdb attached to terminal... up, run.1
            Traceback (most recent call last):
              File "manage.py", line 10, in <module>
                execute_from_command_line(sys.argv)
              File "/app/.heroku/venv/lib/python2.7/site-                                packages/django/core/management/__i
            nit__.py", line 443, in execute_from_command_line
                utility.execute()
              File "/app/.heroku/venv/lib/python2.7/site-packages/django/core/management/__i
            nit__.py", line 382, in execute
                self.fetch_command(subcommand).run_from_argv(self.argv)
              File "/app/.heroku/venv/lib/python2.7/site-packages/django/core/management/__i
            nit__.py", line 261, in fetch_command
                klass = load_command_class(app_name, subcommand)
              File "/app/.heroku/venv/lib/python2.7/site-packages/django/core/management/__i
            nit__.py", line 69, in load_command_class
                module …