如何将 python 版本从默认的 3.5 更改为 google colab 的 3.8

Question

I downloaded python version 3.8 on google colab using:

!apt-get install python3.8

Now I want to change the default python version used in google colab uses from 3.6 to 3.8 . how to do it??

I have read few ans but there are no updates...

Answer 1

Colab has default python 3.7 and alternative 3.6 (on 26.07.2021)

# Choose one of the given alternatives:
!sudo update-alternatives --config python3

# This one used to work but now NOT(for me)!
# !sudo update-alternatives --config python

# Check the result
!python3 --version

# Attention: Install pip (... needed!)
!sudo apt install python3-pip

Answer 2

try these commands

!update-alternatives --install /usr/bin/python python /usr/bin/python3.8 1

then

!update-alternatives --list python

this must display your downloaded python version

after that

!sudo update-alternatives --config python
## !Set python3.8 as default.

finally

!sudo update-alternatives --set python /usr/bin/python3.8

then check your default python version on colab

!python3 --version

Answer 3

There is a way to use any version of python you want, without having to run a kernel locally or going through an ngrok proxy.

Download the colab notebook. Open a text editor to change the kernel specification to:

"kernelspec": {
  "name": "py38",
  "display_name": "Python 3.8"
}

This is the same trick as the one used with Javascript , Java , and Golang .

Then upload the edited notebook to Google Drive. Open the notebook in Google Colab. It cannot find the py38 kernel, so it use normal python3 kernel. You need to install a python 3.8, the google-colab package and the ipykernel under the name you defined above: "py38":

!wget -O mini.sh https://repo.anaconda.com/miniconda/Miniconda3-py38_4.8.2-Linux-x86_64.sh
!chmod +x mini.sh
!bash ./mini.sh -b -f -p /usr/local
!conda install -q -y jupyter
!conda install -q -y google-colab -c conda-forge
!python -m ipykernel install --name "py38" --user

Reload the page, and voilà, you can test the version is correct:

import sys
print("User Current Version:-", sys.version)

A working example can be found there .

Answer 4

In my opinion there is no "good" way to do this. What you can do is start your script with a shebang line. A shebang line will set the python version for the following code. Find some related answers and informations here. How do I tell a Python script to use a particular version

Find here some informations on how to use shebang in colab. https://colab.research.google.com/github/jhermann/blog/blob/master/_notebooks/2020-02-28-env_with_arguments.ipynb#scrollTo=SYv4FagrzLVu

When you have script for more versions of python you might come across this issue. Dealing with multiple python versions when python files have to use #!/bin/env python

Answer 5

This is what I have tried with success:

!sudo apt-get update -y
!sudo apt-get install python3.8
!sudo update-alternatives --install /usr/bin/python3 python3 /usr/bin/python3.8

!update-alternatives --install /usr/bin/python python /usr/bin/python3.8
!update-alternatives --list python
!sudo update-alternatives --config python
!sudo update-alternatives --set python /usr/bin/python3.8
!python3 --version

Answer 6

Here's my solution which completely changes the runtime version, not just the interpreter:

https://stackoverflow.com/a/74538231/9738112