使用virtualenv，我使用默认版本的Python（2.7）运行我的项目。在一个项目中，我需要使用Python 3.4。
我使用brew install python3在Mac上安装它。现在，如何创建使用新版本的virtualenv？
例如sudo virtualenv envPython3
如果我尝试：
virtualenv -p python3 test
我得到：
Running virtualenv with interpreter /usr/local/bin/python3
Using base prefix '/usr/local/Cellar/python3/3.4.0_1/Frameworks/Python.framework/Versions/3.4'
New python executable in test/bin/python3.4
Also creating executable in test/bin/python
Failed to import the site module
Traceback (most recent call last):
File "/Users/user/Documents/workspace/test/test/bin/../lib/python3.4/site.py", line 67, in <module>
import os
File "/Users/user/Documents/workspace/test/test/bin/../lib/python3.4/os.py", line 634, in <module>
from _collections_abc import MutableMapping
ImportError: No module named '_collections_abc'
ERROR: The executable test/bin/python3.4 is not functioning
ERROR: It thinks sys.prefix is '/Users/user/Documents/workspace/test' (should be '/Users/user/Documents/workspace/test/test')
ERROR: virtualenv is not compatible with this system or executable
这就是在python/python3中运行虚拟环境所需的全部内容
首先，如果未安装virtualenv，请运行
pip3 install virtualenv
立即运行：
virtualenv -p python3 <env name> # you can specify full path instead <env_name> to install the files in a different location other than the current location
有时cmd virtualenv失败，如果失败，请使用以下命令：
python3 -m virtualenv <env_name> # you can specify full path instead <env_name> to install the files in a different location other than the current location
现在激活虚拟env：
source <env_name>/bin/activate
Or:
source `pwd`/<env_name>/bin/activate
现在运行
which python
您应该看到目录的完整路径和<env_name>/bin/python后缀
要退出virtualenv，请运行：
deactivate
要解决Python问题，请转到此处
我尝试了以上所有的方法，但仍然没有奏效。所以作为一个蛮力，我只是重新安装了水蟒，重新安装了虚拟。。。并且成功了。
Amans-MacBook-Pro:~ amanmadan$ pip install virtualenv
You are using pip version 6.1.1, however version 8.1.2 is available.
You should consider upgrading via the 'pip install --upgrade pip' command.
Collecting virtualenv
Downloading virtualenv-15.0.3-py2.py3-none-any.whl (3.5MB)
100% |████████████████████████████████| 3.5MB 114kB/s
Installing collected packages: virtualenv
Successfully installed virtualenv-15.0.3
Amans-MacBook-Pro:python amanmadan$ virtualenv my_env
New python executable in /Users/amanmadan/Documents/HadoopStuff/python/my_env/bin/python
Installing setuptools, pip, wheel...done.
Amans-MacBook-Pro:python amanmadan$
