为什么需要虚拟环境

运行不同环境的项目

安装虚拟环境（必要时 sudo）

pip3 install virtualenv

pip3 install vitrualenvwrapper

创建目录存放虚拟环境

mkdir $HOME/.virtualenvs
find / -name .virtualenvs
/root/.virtualenvs

添加全局
find / -name virtualenvwrapper.sh
/usr/local/bin/virtualenvwrapper.sh

使用命令：vim ~/.bashrc在里面添加下面内容

virtualenv definition
export WORKON_HOME=$HOME/.virtualenvs

source /usr/local/bin/virtualenvwrapper.sh

创建虚拟环境

Windows

安装：mkvirtualenv mywork
创建不需下载：mkvirtualenv mywork --no download

python@ubuntu:~$ which python3
/usr/bin/python3
python@ubuntu:~$ mkvirtualenv -p /usr/bin/python3 test
Already using interpreter /usr/bin/python3
Using base prefix '/usr'
New python executable in /home/python/.virtualenvs/test/bin/python3
Also creating executable in /home/python/.virtualenvs/test/bin/python
Installing setuptools, pkg_resources, pip, wheel...done.




Done 安装成功后，自动切换 mywork 虚拟环境

注意：
1、虚拟机能联网
2、创建成功会自动工作在这个虚拟环境中
3、工作在虚拟环境中，提示符前面会有“虚拟环境名称”


进入虚拟环境
workon mywork


退出虚拟环境
deactivate

查看虚拟环境
workon

删除虚拟环境(退出才能删除)
rmvirtualenv mywork

查看虚拟环境目录
(mywork) python@ubuntu:~$ which python
/home/python/.virtualenvs/mywork/bin/python

默认python2
(mywork) python@ubuntu:~$ python
Python 2.7.12 (default, Jul  1 2016, 15:12:24) 
[GCC 5.4.0 20160609] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> 

虚拟环境安装工具包

https://bootstrap.pypa.io/pip/这个网址上找到相应python版本，点开获取如下图：
pip install flask==1.0 -i https://pypi.tuna.tsinghua.edu.cn/simple
(test) python@ubuntu:~$ pip -V
Traceback (most recent call last):
  File "/home/python/.virtualenvs/test/bin/pip", line 7, in <module>
    from pip._internal.cli.main import main
  File "/home/python/.virtualenvs/test/lib/python3.5/site-packages/pip/_internal/cli/main.py", line 57
    sys.stderr.write(f"ERROR: {exc}")
                                   ^
SyntaxError: invalid syntax

加上sudo  可以解决
sudo pip3 install flask==1.0

查看 sudo pip freeze

标签：bin,虚拟环境,virtualenvs,python,mywork,pip,安装
来源： https://blog.csdn.net/u012441595/article/details/120489585