为了防止安装过多的第三方包污染自己的开发环境, python提供的虚拟环境virtualenv, 是个非常好的工具.

用法

创建一个独立的python运行环境

$ virtualenv venv1  
New python executable in venv1/bin/python
Installing setuptools, pip...done.

以下是virtualenv的参数,

You must provide a DEST_DIR
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.
                        与--no-site-packages相反

  --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 (or pip) in the new
                        virtualenv.
  --no-pip              Do not install pip in the new virtualenv.
  --extra-search-dir=DIR
                        Directory to look for setuptools/pip distributions in.
                        This option can be used multiple times.
  --never-download      DEPRECATED. Retained only for backward compatibility.
                        This option has no effect. Virtualenv never downloads
                        pip or setuptools.
  --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.

现在该目录下面出现一个venv1目录
└── venv1
├── bin
├── include
├── lib
└── local

进入新建的venv1环境

source venv1/bin/activate

退出

deactivate