Command "python setup.py egg_info" failed with error code 1 in /tmp/pip-build-vqeCP7/Django/

这个是使用pip安装django的报错

root@ubuntu:/# pip install Django
Collecting Django
  Using cached Django-2.0.tar.gz
    Complete output from command python setup.py egg_info:
    Traceback (most recent call last):
      File "<string>", line 1, in <module>
      File "/tmp/pip-build-vqeCP7/Django/setup.py", line 32, in <module>
        version = __import__('django').get_version()
      File "django/__init__.py", line 1, in <module>
        from django.utils.version import get_version
      File "django/utils/version.py", line 61, in <module>
        @functools.lru_cache()
    AttributeError: 'module' object has no attribute 'lru_cache'
    
    ----------------------------------------
Command "python setup.py egg_info" failed with error code 1 in /tmp/pip-build-vqeCP7/Django/

错误的原因：pip版本是py2.7的管理器，而pip install django 默认是安装django的最新版本

root@ubuntu:/# pip --version
pip 9.0.1 from /usr/local/lib/python2.7/dist-packages (python 2.7)

django的最新版本要支持py3，所以要用pip3（py3的包管理器）安装

root@ubuntu:/# pip3 --version
pip 8.1.1 from /usr/lib/python3/dist-packages (python 3.5)
root@ubuntu:/# pip3 install django
Collecting django
  Downloading Django-2.0-py3-none-any.whl (7.1MB)
    100% |████████████████████████████████| 7.1MB 190kB/s 
Collecting pytz (from django)
  Downloading pytz-2017.3-py2.py3-none-any.whl (511kB)
    100% |████████████████████████████████| 512kB 2.6MB/s 
Installing collected packages: pytz, django
Successfully installed django-2.0 pytz-2017.3          #2.0版本需要py3支持

而py2想安装之前版本的django则需要指定版本

root@ubuntu:/# pip install django==1.10.6
Collecting django==1.10.6
  Downloading Django-1.10.6-py2.py3-none-any.whl (6.8MB)
    100% |████████████████████████████████| 6.8MB 135kB/s 
Installing collected packages: django
Successfully installed django-1.10.6
root@ubuntu:/# pip --version
pip 9.0.1 from /usr/local/lib/python2.7/dist-packages (python 2.7)