windows安装python虚拟环境

Windows：

先安装的Python3.6,后安装Python2.7

• 进入cmd
• 安装virtualenv

创建虚拟环境

virtualenv --python=D:\Python27\python.exe venv

激活虚拟环境

D:\deeplab\deeplab-resnet-master>cd .\venv

D:\deeplab\deeplab-resnet-master\venv>.\Scripts\activate.bat  

(venv) D:\deeplab\deeplab-resnet-master\venv>python
Python 2.7.14 (v2.7.14:84471935ed, Sep 16 2017, 20:19:30) [MSC v.1500 32 bit (Intel)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>>

关闭虚拟环境：deactivate

(venv) D:\deeplab\deeplab-resnet-master\venv>deactivate
D:\deeplab\deeplab-resnet-master\venv>python
Python 3.6.3 (v3.6.3:2c5fed8, Oct  3 2017, 18:11:49) [MSC v.1900 64 bit (AMD64)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>>

---

Ubuntu

sky@sky-X450CC:~/python27env$ virtualenv --no-site-packages venv
New python executable in /home/sky/python27env/venv/bin/python
Installing setuptools, pip, wheel...done.
sky@sky-X450CC:~/python27env$ source ./venv/bin/activate
(venv) sky@sky-X450CC:~/python27env$ python
Python 2.7.12 (default, Nov 20 2017, 18:23:56) 
[GCC 5.4.0 20160609] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> exit()
(venv) sky@sky-X450CC:~/python27env$ deactivate
sky@sky-X450CC:~/python27env$ 

https://code.visualstudio.com/docs/python/environments

virtualenv --help
Usage: virtualenv [OPTIONS] DEST_DIR

Options:
  --version             show program's version number and exit
  -h, --help            show this help message and exit
  -v, --verbose         Increase verbosity.
  -q, --quiet           Decrease verbosity.
  -p PYTHON_EXE, --python=PYTHON_EXE
                        The Python interpreter to use, e.g.,
                        --python=python2.5 will use the python2.5 interpreter
                        to create the new environment.  The default is the
                        interpreter that virtualenv was installed with
                        (/usr/bin/python)
  --clear               Clear out the non-root install and start from scratch.
  --no-site-packages    DEPRECATED. Retained only for backward compatibility.
                        Not having access to global site-packages is now the
                        default behavior.
  --system-site-packages
                        Give the virtual environment access to the global
                        site-packages.
  --always-copy         Always copy files rather than symlinking.
  --unzip-setuptools    Unzip Setuptools when installing it.
  --relocatable         Make an EXISTING virtualenv environment relocatable.
                        This fixes up scripts and makes all .pth files
                        relative.
  --no-setuptools       Do not install setuptools in the new virtualenv.
  --no-pip              Do not install pip in the new virtualenv.
  --no-wheel            Do not install wheel in the new virtualenv.
  --extra-search-dir=DIR
                        Directory to look for setuptools/pip distributions in.
                        This option can be used multiple times.
  --download            Download preinstalled packages from PyPI.
  --no-download, --never-download
                        Do not download preinstalled packages from PyPI.
  --prompt=PROMPT       Provides an alternative prompt prefix for this
                        environment.
  --setuptools          DEPRECATED. Retained only for backward compatibility.
                        This option has no effect.
  --distribute          DEPRECATED. Retained only for backward compatibility.
                        This option has no effect.

virtualenv --always-copy --python=python3.5 ./py35/