python 使用virtualenvrapper虚拟环境管理工具

centos 默认安装的python是2.6版本的

使用virtualenv 环境管理工具建立python虚拟环境的时候会遇到一些错误，DEPRECATION: Python 2.6 is no longer supported by the Python core team, please upgrade your Python. A future version of pip will drop support for Python 2.6

好像是python2.6 官方不在支持 virtualenv

1.升级python版本 到2.7

2.删除删除掉以前的setuptools，pip（/usr/bin下也要删干净）

pip uninstall setuptools
  pip uninstall pip

重新安装

下载pip

wget "https://pypi.python.org/packages/source/p/pip/pip-1.5.4.tar.gz#md5=834b2904f92d46aaa333267fb1c922bb" --no-check-certificate

解压

tar -zxvf pip-1.5.4.tar.gz

cd pip-1.5.4

python setup.py install

（此时报错，找不到setuptools.）

首先安装setuptools

下载setuptools安装脚本

wget –q http://peak.telecommunity.com/dist/ez_setup.py

python ez_setup.py 执行

再次执行 python setup.py install

OK

最后使用  mkvirtualenv --help命令查看，可以使用virtualenv了

[root@localhost ~]# mkvirtualenv --help
Usage: mkvirtualenv [-a project_path] [-i package] [-r requirements_file] [virtualenv options] env_name

-a project_path

Provide a full path to a project directory to associate with
the new environment.

-i package

Install a package after the environment is created.
This option may be repeated.

-r requirements_file

Provide a pip requirements file to install a base set of packages
into the new environment.

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.

但是  读入环境还是报错

[root@localhost ~]# source /root/.bashrc
/usr/local/bin/python: No module named virtualenvwrapper
virtualenvwrapper.sh: There was a problem running the initialization hooks.

If Python could not import the module virtualenvwrapper.hook_loader,
check that virtualenvwrapper has been installed for
VIRTUALENVWRAPPER_PYTHON=/usr/local/bin/python and that PATH is
set properly.

查了下好像是virtualenvwrapper 版本低了的原因 升级了virtualenvwrapper

[root@localhost ~]# /usr/local/bin/pip install virtualenvwrapper --upgrade

就OK 了

建立虚拟运行环境

[root@localhost ~]# mkvirtualenv newenv

[root@localhost ~]# mkvirtualenv newenv
New python executable in /root/.virtualenvs/newenv/bin/python
Installing setuptools, pip, wheel...done.
virtualenvwrapper.user_scripts creating /root/.virtualenvs/newenv/bin/predeactivate
virtualenvwrapper.user_scripts creating /root/.virtualenvs/newenv/bin/postdeactivate
virtualenvwrapper.user_scripts creating /root/.virtualenvs/newenv/bin/preactivate
virtualenvwrapper.user_scripts creating /root/.virtualenvs/newenv/bin/postactivate
virtualenvwrapper.user_scripts creating /root/.virtualenvs/newenv/bin/get_env_details

从这里可以看出 新建的虚拟运行环境目录在  /root/.virtualenvs目录下， 虚拟运行环境目录是根据环境变量WORKON_HOME设定决定的

这是我的环境变量：

export WORKON_HOME=$HOME/.virtualenvs
export VIRTUALENVWRAPPER_PYTHON=/usr/local/bin/python
export VIRTUALENVWRAPPER_VIRTUALENV=/usr/bin/virtualenv
source /usr/bin/virtualenvwrapper.sh

此时进入虚拟运行环境的命令变成了 workon

[root@localhost .virtualenvs]# workon newenv
(newenv) [root@localhost .virtualenvs]#

也可以直接 cd  /root/.virtualenvs

退出环境 deactivate

(newenv) [root@localhost .virtualenvs]# deactivate
[root@localhost .virtualenvs]#