manjaro安装python虚拟环境

操作系统：manjaro 17.1.7

python版本：3.6.4

功能需求：创建一个虚拟环境

实现途径：

mkdir nova_virtual_env
python -m venv nova_virtual_env

不过很多时候，python3不是一个很好的使用选择：

这时候便需要使用python2了。这里补充一下ｍanjaro上python2虚拟环境的创建方式：

１．先安装python2的一下关于虚拟环境的包：

sudo pacman -S --needed --noconfirm python2-pip python2-setuptools python2-virtualenv python-virtualenvwrapper

２．开始创建虚拟环境：

mkdir nova_virtual_env

python2 -m virtualenv --clear nova_virtual_env

tips:

这里使用　--clear参数是因为之前在nova_virtual_env中已经安装了虚拟环境了，所以这里需要清除下。

神器送上：

  Openstack python2 -m virtualenv --help                  
Usage: virtualenv.py [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/python2)
  --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.