Python virtual environment installation and uninstallation methods and problems encountered

Ubuntu16.04 install and uninstall pip

Experimental environment

Ubuntu 16.04; VMware 15;

Problem Description

I installed Ubuntu 16.04 on a virtual machine. After a while, I reopened it and prepared to compile a python program. When installing the required packages, I found that pip pip3 all pointed to python 2.7.

hadoop@ubuntu:~$ pip3.5 -V
pip 19.1.1 from /usr/local/lib/python2.7/dist-packages/pip (python 2.7)
hadoop@ubuntu:~$ pip -V
pip 19.1.1 from /usr/local/lib/python2.7/dist-packages/pip (python 2.7)

After searching online and reading various tutorials, I still cannot get pip3 to link to python3. The final solution to the problem was an accidental result after spending time.

Problem Solving

The solution most often mentioned in online tutorials is:

Install pip

sudo apt-get install python3-pip

Upgrade pip

sudo pip3 install --upgrade pip

uninstall

sudo apt-get remove python3-pip

Generally, this will default pip3 to python3, but it doesn't solve my problem. You can try it, maybe it can solve your problem. If not, read on.

What actually solved my problem:

Install pip3

Use the following statement to install. If you want to configure pip3 for the system's built-in python3.5, just execute curl https://bootstrap.pypa.io/get-pip.py | sudo python3.6. After execution, if pip points to python3.5, we only need to execute curl https://bootstrap.pypa.io/get-pip.py | sudo python2.7 again.

# Check and install python3.6
sudo apt-get update
sudo apt-get install python3.6
curl https://bootstrap.pypa.io/get-pip.py | sudo python3.6

After finishing, verify the pip version:

hadoop@ubuntu:~$ pip3.5 -V
pip 19.1.1 from /usr/local/lib/python3.5/dist-packages/pip (python 3.5)
hadoop@ubuntu:~$ pip -V
pip 19.1.1 from /usr/local/lib/python2.7/dist-packages/pip (python 2.7)

It was just a small problem, but it took me a long time to record it.

To avoid some exceptions, it is recommended not to modify the system's built-in Python environment

Summarize

The above is the Python virtual environment installation and uninstallation method and problems encountered introduced by the editor. I hope it will be helpful to everyone!