英文:

How to downgrade python 3.11.3 to python 3.9 on Linux mint

问题

I have a python library I need python 3.9 to run. However, the default python that came with my system is 3.11.3 (as found by doing python --version). I need python to be downgraded, but I can't uninstall python 3.11.3:

我有一个需要运行Python 3.9的Python库。但是，我的系统默认安装的Python版本是3.11.3（通过执行 python --version 命令确认）。我需要降级Python版本，但无法卸载Python 3.11.3：

sudo apt-get remove python3 results in:

sudo apt-get remove python3 命令会导致以下结果：

Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
 mintsources : Depends: python3-apt but it is not going to be installed
               Depends: python3-gi but it is not going to be installed
               Depends: python3-gi-cairo but it is not going to be installed
               Depends: python3-pycurl but it is not going to be installed
               Depends: mint-common (>= 2) but it is not going to be installed
               Depends: gir1.2-xapp-1.0 but it is not going to be installed
E: Error, pkgProblemResolver::Resolve generated breaks, this may be caused by held packages.

What can I do to get python 3.11.3 uninstalled and make python 3.9 default for my system (I have already installed python 3.9 with pyenv but the active version of python is still 3.11.3)

我该怎么做才能卸载Python 3.11.3 并将Python 3.9 设置为系统默认版本（我已经使用 pyenv 安装了Python 3.9，但当前激活的Python版本仍然是3.11.3）？

Here is what I've done so far, which is confusing to me why pyenv would show it as 3.9.0, but python as 3.11.3:

以下是我迄今为止所做的操作，我感到困惑的是为什么pyenv显示为3.9.0，但python显示为3.11.3：

(base) matteo@masked-hero:~$ pyenv local 3.9.0
(base) matteo@masked-hero:~$ pyenv versions
  system
* 3.9.0 (set by /home/matteo/.python-version)
  3.9.0/envs/pypy
  pypy --> /home/matteo/.pyenv/versions/3.9.0/envs/pypy
(base) matteo@masked-hero:~$ python --version
Python 3.11.3

After doing init --reverse I get:

执行 init --reverse 后，我得到：

matteo@masked-hero:~$ python --version
Python 3.11.3
matteo@masked-hero:~$ pyenv local 3.9.0
matteo@masked-hero:~$ python --version
Python 3.11.3
matteo@masked-hero:~$ python3 --version
Python 3.11.3

My bashrc file has:

我的bashrc文件内容如下：

matteo@masked-hero:~$ cat .bashrc
# ~/.bashrc: executed by bash(1) for non-login shells.
# see /usr/share/doc/bash/examples/startup-files (in the package bash-doc)
# for examples

# If not running interactively, don't do anything
case $- in
    *i*) ;;
      *) return;;
esac

# don't put duplicate lines or lines starting with space in the history.
# See bash(1) for more options
HISTCONTROL=ignoreboth

# append to the history file, don't overwrite it
shopt -s histappend

# for setting history length see HISTSIZE and HISTFILESIZE in bash(1)
HISTSIZE=1000
HISTFILESIZE=2000

# check the window size after each command and, if necessary,
# update the values of LINES and COLUMNS.
shopt -s checkwinsize

# If set, the pattern "**" used in a pathname expansion context will
# match all files and zero or more directories and subdirectories.
#shopt -s globstar

# make less more friendly for non-text input files, see lesspipe(1)
[ -x /usr/bin/lesspipe ] && eval "$(SHELL=/bin/sh lesspipe)"

# set variable identifying the chroot you work in (used in the prompt below)
if [ -z "${debian_chroot:-}" ] && [ -r /etc/debian_chroot ]; then
    debian_chroot=$(cat /etc/debian_chroot)
fi

# set a fancy prompt (non-color, unless we know we "want" color)
case "$TERM" in
    xterm-color|*-256color) color_prompt=yes;;
esac

# uncomment for a colored prompt, if the terminal has the capability; turned
# off by default to not distract the user: the focus in a terminal window
# should be on the output of commands, not on the prompt
#force_color_prompt=yes

if [ -n "$force_color_prompt" ]; then
    if [ -x /usr/bin/tput ] && tput setaf 1 >/dev/null; then
	# We have color support; assume it's compliant with Ecma-48
	# (ISO/IEC-6429). (Lack of such support is extremely rare, and such
	# a case would tend to support setf rather than setaf.)
	color_prompt=yes
    else
	color_prompt=
    fi
fi

if [ "$color_prompt" = yes ]; then
    PS1='${debian_chroot:+($debian_chroot)}\[3[01;32m\]\u@\h\[3[00m\]:\[3[01;34m\]\w\[3[00m\]$ '
else
    PS1='${debian_chroot:+($debian_chroot)}\u@\h:\w$ '
fi
unset color_prompt force_color_prompt

# If this is an xterm set the title to user@host:dir
case "$TERM" in
xterm*|rxvt*)
    PS1="\[\e]0;${debian_chroot:+($debian_chroot)}\u@\h: \w\a\]$PS1"
    ;;
*)
    ;;
esac

# enable

<details>
<summary>英文:</summary>

I have a python library I need python 3.9 to run. However, the default python that came with my system is 3.11.3 (as found by doing `python --version`). I need python to be downgraded, but I can&#39;t uninstall python 3.11.3:
`sudo apt-get remove python3` results in:

Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
mintsources : Depends: python3-apt but it is not going to be installed
Depends: python3-gi but it is not going to be installed
Depends: python3-gi-cairo but it is not going to be installed
Depends: python3-pycurl but it is not going to be installed
Depends: mint-common (>= 2) but it is not going to be installed
Depends: gir1.2-xapp-1.0 but it is not going to be installed
E: Error, pkgProblemResolver::Resolve generated breaks, this may be caused by held packages.

What can I do to get python 3.11.3 uninstalled and make python 3.9 default for my system (I have already installed python 3.9 with pyenv but the active version of python is still 3.11.3)

Here is what I've done so far, which is confusing to me why pyenv would show it as 3.9.0, but python as 3.11.3:

(base) matteo@masked-hero:~$ pyenv local 3.9.0
(base) matteo@masked-hero:~$ pyenv versions
system

• 3.9.0 (set by /home/matteo/.python-version)
  3.9.0/envs/pypy
  pypy --> /home/matteo/.pyenv/versions/3.9.0/envs/pypy
  (base) matteo@masked-hero:~$ python --version
  Python 3.11.3

After doing `init --reverse` I get:

matteo@masked-hero:~$ python --version
Python 3.11.3
matteo@masked-hero:~$ pyenv local 3.9.0
matteo@masked-hero:~$ python --version
Python 3.11.3
matteo@masked-hero:~$ python3 --version
Python 3.11.3

My bashrc file has:

matteo@masked-hero:~$ cat .bashrc

~/.bashrc: executed by bash(1) for non-login shells.

see /usr/share/doc/bash/examples/startup-files (in the package bash-doc)

for examples

If not running interactively, don't do anything

case $- in
i) ;;
*) return;;
esac

don't put duplicate lines or lines starting with space in the history.

See bash(1) for more options

HISTCONTROL=ignoreboth

append to the history file, don't overwrite it

shopt -s histappend

for setting history length see HISTSIZE and HISTFILESIZE in bash(1)

HISTSIZE=1000
HISTFILESIZE=2000

check the window size after each command and, if necessary,

update the values of LINES and COLUMNS.

shopt -s checkwinsize

If set, the pattern "**" used in a pathname expansion context will

match all files and zero or more directories and subdirectories.

#shopt -s globstar

make less more friendly for non-text input files, see lesspipe(1)

[ -x /usr/bin/lesspipe ] && eval "$(SHELL=/bin/sh lesspipe)"

set variable identifying the chroot you work in (used in the prompt below)

if [ -z "${debian_chroot:-}" ] && [ -r /etc/debian_chroot ]; then
debian_chroot=$(cat /etc/debian_chroot)
fi

set a fancy prompt (non-color, unless we know we "want" color)

case "$TERM" in
xterm-color|*-256color) color_prompt=yes;;
esac

uncomment for a colored prompt, if the terminal has the capability; turned

off by default to not distract the user: the focus in a terminal window

should be on the output of commands, not on the prompt

#force_color_prompt=yes

if [ -n "$force_color_prompt" ]; then
if [ -x /usr/bin/tput ] && tput setaf 1 >&/dev/null; then
# We have color support; assume it's compliant with Ecma-48
# (ISO/IEC-6429). (Lack of such support is extremely rare, and such
# a case would tend to support setf rather than setaf.)
color_prompt=yes
else
color_prompt=
fi
fi

if [ "$color_prompt" = yes ]; then
PS1='${debian_chroot:+($debian_chroot)}[\033[01;32m]\u@\h[\033[00m]:[\033[01;34m]\w[\033[00m]$ '
else
PS1='${debian_chroot:+($debian_chroot)}\u@\h:\w$ '
fi
unset color_prompt force_color_prompt

If this is an xterm set the title to user@host:dir

case "$TERM" in
xterm*|rxvt*)
PS1="[\e]0;${debian_chroot:+($debian_chroot)}\u@\h: \w\a]$PS1"
;;
*)
;;
esac

enable color support of ls and also add handy aliases

if [ -x /usr/bin/dircolors ]; then
test -r ~/.dircolors && eval "$(dircolors -b ~/.dircolors)" || eval "$(dircolors -b)"
alias ls='ls --color=auto'
#alias dir='dir --color=auto'
#alias vdir='vdir --color=auto'

alias grep='grep --color=auto'
alias fgrep='fgrep --color=auto'
alias egrep='egrep --color=auto'

fi

colored GCC warnings and errors

#export GCC_COLORS='error=01;31:warning=01;35:note=01;36:caret=01;32:locus=01:quote=01'

some more ls aliases

alias ll='ls -alF'
alias la='ls -A'
alias l='ls -CF'

Add an "alert" alias for long running commands. Use like so:

sleep 10; alert

alias alert='notify-send --urgency=low -i "$([ $? = 0 ] && echo terminal || echo error)" "$(history|tail -n1|sed -e '''s/^\s*[0-9]+\s*//;s/[;&|]\s*alert$//''')"'

Alias definitions.

You may want to put all your additions into a separate file like

~/.bash_aliases, instead of adding them here directly.

See /usr/share/doc/bash-doc/examples in the bash-doc package.

if [ -f ~/.bash_aliases ]; then
. ~/.bash_aliases
fi

enable programmable completion features (you don't need to enable

this, if it's already enabled in /etc/bash.bashrc and /etc/profile

sources /etc/bash.bashrc).

if ! shopt -oq posix; then
if [ -f /usr/share/bash-completion/bash_completion ]; then
. /usr/share/bash-completion/bash_completion
elif [ -f /etc/bash_completion ]; then
. /etc/bash_completion
fi
fi
eval "$(pyenv virtualenv-init -)"
export PATH=/home/matteo/anaconda3/bin:/home/matteo/anaconda3/condabin:/usr/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin:/path/to/new/directory
export PATH="$HOME/.pyenv/bin:$PATH"

</details>


# 答案1
**得分**: 1

使用brew，您可以安装pyenv，然后在创建环境时指定要运行的Python版本。您的输出显示您位于一个名为base的环境中，因此您正在询问您的操作系统上安装的默认Python的版本是什么。

<details>
<summary>英文:</summary>

Using brew you can install pyenv and then specify which version of python you want to run in a given environment while you are making it.  Your output says that you are in an environment called base, so you are asking the default python installed on your OS what version it is.

</details>



# 答案2
**得分**: 0

如果您使用的是Mac，您将使用Brew安装Pyenv并选择您的版本。这与Linux相同，但提示中的命令不同，您应该按照这里的步骤操作：https://itslinuxfoss.com/install-use-pyenv-ubuntu/。但如果您使用的是Windows，您可以直接安装其他版本，删除您的环境并选择另一个脚本来启动IDE中的Python。

<details>
<summary>英文:</summary>

Well , depends what OS  you are using. 

If you are using Mac you will use Brew to install Pyenv and choose your version . This is the same with linux but the command in prompt is different , you should follow this steps here https://itslinuxfoss.com/install-use-pyenv-ubuntu/.
But if you are using Windows, you can install other version directly, delete your enviroment and choose another script to start the Python in IDE 

</details>