Python 很好用的程式語言。
此篇不討論如何撰寫 Python 的程式，而是當使用或變動系統的 Python 時，可能發生的問題。
我們是要用 Python，而不是解決 Python 的問題。但問題不解決，怎麼用。而此篇剛好提供小小的建議。
Python 版本過新，降低版本到 Python=x.x。一句很簡單的解法，但是問題真的被解決了嗎？
[維基百科] Python
Python（英國發音：/ˈpaɪθən/；美國發音：/ˈpaɪθɑːn/），是一種廣泛使用的直譯式、進階和通用的程式語言。Python支援多種程式設計範式，包括結構化、程序式、反射式、物件導向和函數式程式設計。它擁有動態型別系統和垃圾回收功能，能夠自動管理記憶體使用，並且其本身擁有一個巨大而廣泛的標準庫。它的語言結構以及物件導向的方法，旨在幫助程式設計師為小型的和大型的專案編寫邏輯清晰的程式碼。
python3 & pip3 需要共生共存，兩邊的版本要一致。
$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 20.04.6 LTS
Release: 20.04
Codename: focal$ sudo apt update
$ sudo apt upgrade
# install default version
$ sudo apt install -y python3
$ sudo apt install -y python3-dev
$ sudo apt install python3-venv
$ sudo apt install -y python3-virtualenv
# install pip3
$ sudo apt install -y python3-pip$ python3 --version
Python 3.8.10
$ pip3 --version
pip 20.0.2 from /usr/lib/python3/dist-packages/pip (python 3.8)
$ virtualenv --version
virtualenv 20.24.7 from /home/lanka/.local/lib/python3.8/site-packages/virtualenv/__init__.py$ which python3
/usr/bin/python3
$ ll /usr/bin/*python3*
-rwxr-xr-x 1 root root 387 三 4 2020 /usr/bin/ipython3*
lrwxrwxrwx 1 root root 9 七 14 2022 /usr/bin/python3 -> python3.8*
-rwxr-xr-x 1 root root 5494584 五 26 2023 /usr/bin/python3.8*
lrwxrwxrwx 1 root root 33 五 26 2023 /usr/bin/python3.8-config -> x86_64-linux-gnu-python3.8-config*
lrwxrwxrwx 1 root root 16 三 13 2020 /usr/bin/python3-config -> python3.8-config*
-rwxr-xr-x 1 root root 384 一 25 2023 /usr/bin/python3-futurize*
-rwxr-xr-x 1 root root 388 一 25 2023 /usr/bin/python3-pasteurize*
-rwxr-xr-x 1 root root 1797 八 6 2019 /usr/bin/python3-unidiff*
-rwxr-xr-x 1 root root 3241 五 26 2023 /usr/bin/x86_64-linux-gnu-python3.8-config*
lrwxrwxrwx 1 root root 33 三 13 2020 /usr/bin/x86_64-linux-gnu-python3-config -> x86_64-linux-gnu-python3.8-config*當系統已經安裝很多的 packages 後，不建議升級系統的 python，因為
a. python 本身的變動性很大，常存在向下不相容。
b. python 套件和 python 的版本過度相依。
c. python 套件的開發很快，但是生命週期也短。有可能 3.8 還存在，但是之後就不再更新。
d. python 套件本身引用過多的套件時，當一個套件升級失敗就有可能造成整個系統混亂。
e. /usr/lib/python3/dist-packages 裏的更新問題。
f. 更改 python 後 pip3 有可能不能用。
但是事情總是要解決，建議參考使用 Virtual Environment。
$ sudo apt update
$ sudo apt -y upgrade
$ sudo apt install -y software-properties-common
$ sudo add-apt-repository ppa:deadsnakes/ppa$ sudo apt install -y python3.10-full
$ sudo apt install -y python3.10-*
$ sudo apt install -y python3.14-full這邊使用 update-alternatives 進行系統調整。
# 3.8.10 -> 3.10
$ sudo update-alternatives --config python3
update-alternatives: error: no alternatives for python3
$ ll /usr/bin/python3*
$ ll /usr/bin/python2*
$ ll /usr/bin/python*
# --install <link> <name> <path> <priority>
# priority 越大則優先
# /usr/bin/python3
$ sudo update-alternatives --install /usr/bin/python3 python3 /usr/bin/python3.8 8
$ sudo update-alternatives --install /usr/bin/python3 python3 /usr/bin/python3.10 10
$ sudo update-alternatives --install /usr/bin/python3 python3 /usr/bin/python3.12 12
$ sudo update-alternatives --install /usr/bin/python3 python3 /usr/bin/python3.13 13
$ sudo update-alternatives --install /usr/bin/python3 python3 /usr/bin/python3.14 14
# /usr/bin/python
$ sudo update-alternatives --install /usr/bin/python python /usr/bin/python3.8 8
$ sudo update-alternatives --install /usr/bin/python python /usr/bin/python3.10 10
$ sudo update-alternatives --install /usr/bin/python python /usr/bin/python3.12 12
$ sudo update-alternatives --install /usr/bin/python python /usr/bin/python3.13 13
$ sudo update-alternatives --install /usr/bin/python python /usr/bin/python3.14 14
$ ll /etc/alternatives/python*
lrwxrwxrwx 1 root root 18 四 24 13:20 /etc/alternatives/python -> /usr/bin/python3.8*
lrwxrwxrwx 1 root root 18 四 24 13:17 /etc/alternatives/python3 -> /usr/bin/python3.8*
$ update-alternatives --list python
/usr/bin/python3.10
/usr/bin/python3.8
$ update-alternatives --list python3
/usr/bin/python3.10
/usr/bin/python3.8
$ sudo update-alternatives --config python
There are 2 choices for the alternative python (providing /usr/bin/python).
Selection Path Priority Status
------------------------------------------------------------
* 0 /usr/bin/python3.8 2 auto mode
1 /usr/bin/python3.10 1 manual mode
2 /usr/bin/python3.8 2 manual mode
Press <enter> to keep the current choice[*], or type selection number: 1
update-alternatives: using /usr/bin/python3.10 to provide /usr/bin/python (python) in manual mode
$ sudo update-alternatives --config python3
There are 2 choices for the alternative python3 (providing /usr/bin/python3).
Selection Path Priority Status
------------------------------------------------------------
0 /usr/bin/python3.10 2 auto mode
1 /usr/bin/python3.10 2 manual mode
* 2 /usr/bin/python3.8 1 manual mode
Press <enter> to keep the current choice[*], or type selection number: 1
update-alternatives: using /usr/bin/python3.10 to provide /usr/bin/python3 (python3) in manual mode
# remove /usr/bin/python3 from python
$ sudo update-alternatives --remove python /usr/bin/python3$ export PJ_PYTHON_VER=`python -c 'import sys; print("{0[0]}.{0[1]}".format(sys.version_info))'`
# 有時試著移除 ~/.local/lib/python${PJ_PYTHON_VER}
$ echo $PJ_PYTHON_VER
$ mv ~/.local/lib/python${PJ_PYTHON_VER} ~/.local/lib/python${PJ_PYTHON_VER}-bak
# reinstall pip
$ curl -sS https://bootstrap.pypa.io/get-pip.py | python${PJ_PYTHON_VER}# upgrade pip3
$ pip install --upgrade pip# to check again
$ ll /etc/alternatives/python*
lrwxrwxrwx 1 root root 18 四 25 11:35 /etc/alternatives/python -> /usr/bin/python3.8*
lrwxrwxrwx 1 root root 19 四 25 11:36 /etc/alternatives/python3 -> /usr/bin/python3.10*
$ python3 --version
Python 3.10.14
$ pip3 --version
pip 24.0 from /home/lanka/.local/lib/python3.10/site-packages/pip (python 3.10)
$ pip --version
pip 24.0 from /home/lanka/.local/lib/python3.10/site-packages/pip (python 3.10)
$ virtualenv --version
virtualenv 20.26.0 from /home/lanka/.local/lib/python3.10/site-packages/virtualenv/__init__.py$ pip install --upgrade pip
error: externally-managed-environment
× This environment is externally managed
╰─> To install Python packages system-wide, try apt install
python3-xyz, where xyz is the package you are trying to
install.
If you wish to install a non-Debian-packaged Python package,
create a virtual environment using python3 -m venv path/to/venv.
Then use path/to/venv/bin/python and path/to/venv/bin/pip. Make
sure you have python3-full installed.
If you wish to install a non-Debian packaged Python application,
it may be easiest to use pipx install xyz, which will manage a
virtual environment for you. Make sure you have pipx installed.
See /usr/share/doc/python3.12/README.venv for more information.
note: If you believe this is a mistake, please contact your Python installation or OS distribution provider. You can override this, at the risk of breaking your Python installation or OS, by passing --break-system-packages.
hint: See PEP 668 for the detailed specification.$ sudo apt-get --yes install pipx
$ pipx ensurepath$ pip install --upgrade yt-dlp
$ tree -L 2 ~/.local/bin/
/home/lanka/.local/bin/
└── yt-dlp -> /home/lanka/.local/share/pipx/venvs/yt-dlp/bin/yt-dlp
1 directory, 1 file
# 如果 pipx install yt-dlp，才會在 venvs/yt-dlp
$ tree -L 2 ~/.local/share/pipx/
/home/lanka/.local/share/pipx/
├── shared
│ ├── bin
│ ├── include
│ ├── lib
│ ├── lib64 -> lib
│ └── pyvenv.cfg
└── venvs
└── yt-dlp
8 directories, 1 file
$ tree -L 2 ~/.local/state/
/home/lanka/.local/state/
├── pipx
│ └── log
└── wireplumber
└── restore-stream
4 directories, 1 file
$ pipx uninstall yt-dlp建立一個獨立的開發環境，如前章節有提到，現有能穩定執行的套件，不見得匹配最新的的 python3。
$ sudo apt install -y python3.10-full
$ which python3.10
/usr/bin/python3.10
# install python Virtual Environment
$ pip install --upgrade virtualenv
$ pip install --upgrade setuptools
$ mkdir -p /work/bin/python/$PJ_PYTHON_VER
# create A Virtual Environment in /work/bin/python/3.10
$ cd /work/bin/python/$PJ_PYTHON_VER; virtualenv --python=python$PJ_PYTHON_VER .
$ cd /work/bin/python/$PJ_PYTHON_VER; tree -L 2 ./
./
├── bin
│ ├── activate
│ ├── activate.csh
│ ├── activate.fish
│ ├── activate.nu
│ ├── activate.ps1
│ ├── activate_this.py
│ ├── pip
│ ├── pip3
│ ├── pip-3.10
│ ├── pip3.10
│ ├── python -> /usr/bin/python3.10
│ ├── python3 -> python
│ ├── python3.10 -> python
│ ├── wheel
│ ├── wheel3
│ ├── wheel-3.10
│ └── wheel3.10
├── lib
│ └── python3.10
└── pyvenv.cfg
3 directories, 18 files
$ . /work/bin/python/$PJ_PYTHON_VER/bin/activate
(3.10) $ pip3 list
Package Version
---------- -------
pip 24.0
setuptools 69.5.1
wheel 0.43.0
環境變數將會被影響
PS1="(3.10) \[\e]0;\u@\h: \w\a\]${debian_chroot:+($debian_chroot)}\u@\h:\w\$ "
PATH="/work/python/3.10/bin:/home/lanka/.local/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin"
VIRTUAL_ENV="/work/python/3.10"
VIRTUAL_ENV_PROMPT="3.10"
$ python --version
Python 3.10.14
$ pip3 --version
pip 24.0 from /work/bin/python/3.10/lib/python3.10/site-packages/pip (python 3.10)
$ pip install netifaces
$ cd /work
$ vi helloworld.py
import sys
import netifaces
def main(argv):
print(netifaces.interfaces())
if __name__ == "__main__":
main(sys.argv[0:])
$ python helloworld.py (3.10) $ deactivate$ export PYTHON_LIB="/work/python"
$ pip install --target ${PYTHON_LIB} -r requirements.txt- requirements.txt
$ vi requirements.txt
boto3==1.26.123
#https://pypi.org/project/netifaces/
netifaces==0.11.0
$ (export PYTHONPATH="/work/python"; python ./helloworld.py)Find, install and publish Python packages with the Python Package Index
單純的下載
$ pip download tuya-device-sharing-sdk==0.2.1
# --no-deps 不下載依賴 packages
$ pip download --no-deps meson==1.3.0
# 預設會下載 wheel (.whl) 檔，而不是 .tar.gz 原始碼包
# 強制下載 source tarball
$ pip download --no-deps --no-binary=:all: cmake==4.0.3
$ tree -L 1./
.
├── certifi-2025.8.3-py3-none-any.whl
├── charset_normalizer-3.4.3-cp310-cp310-manylinux2014_x86_64.manylinux_2_17_x86_64.manylinux_2_28_x86_64.whl
├── cmake-4.0.3.tar.gz
├── idna-3.10-py3-none-any.whl
├── meson-1.3.0-py3-none-any.whl
├── paho_mqtt-2.1.0-py3-none-any.whl
├── requests-2.32.4-py3-none-any.whl
├── tuya_device_sharing_sdk-0.2.1-py2.py3-none-any.whl
└── urllib3-2.5.0-py3-none-any.whl
0 directories, 9 files$ pip install markdown
# for special version
$ pip install meson==1.3.0
$ pip list
Package Version
-------- -------
Markdown 3.5.1
meson 1.3.0
pip 23.3.1
$ cmake --version
cmake version 3.16.3
# list the outdated packages
$ pip list -o
# upgrade all of the outdated packages
$ pip list -o | cut -f1 -d' ' | xargs -n1 pip install -U$ pip uninstall meson$ pip install --upgrade meson
$ pip install --upgrade markdown
$ pip install --upgrade cmake
# for kconfig
$ pip install --upgrade kconfiglib
# upgrade wheel setuptools
$ pip install --upgrade wheel setuptools launchpadlib six
# upgrade pycairo
$ sudo apt-get install libgirepository1.0-dev libcairo2-dev
# pygobject fail, 請試著安裝
$ sudo apt-get install libgirepository-2.0-dev
$ pip install --upgrade six
$ pip install --upgrade pygobject
$ pip install --upgrade pycairo
$ pip install --upgrade boto3 netifaces
$ pip install --upgrade pyproject-toml
$ pip install --upgrade pylint$ pip show meson
Name: meson
Version: 1.8.2
Summary: A high performance build system
Home-page: https://mesonbuild.com
Author: Jussi Pakkanen
Author-email: jpakkane@gmail.com
License: Apache License, Version 2.0
Location: /home/lanka/.local/lib/python3.12/site-packages
Requires:
Required-by:$ ll /usr/lib/python3/dist-packages
$ export PJ_PYTHON_VER=`python -c 'import sys; print("{0[0]}.{0[1]}".format(sys.version_info))'`; echo $PJ_PYTHON_VER
$ ll ~/.local/lib/python${PJ_PYTHON_VER}
$ pip list列出常用的
- boto3
AWS SDK，看關操作請見 awsP9
[PyPi] Boto3 is the Amazon Web Services (AWS) Software Development Kit (SDK) for Python, which allows Python developers to write software that makes use of services like Amazon S3 and Amazon EC2. You can find the latest, most up to date, documentation at our doc site, including a list of services that are supported.
- cmake
一個構建工具，看關操作請見 makeXcmakeXmesonXgn
[PyPi] CMake is used to control the software compilation process using simple platform and compiler independent configuration files, and generate native makefiles and workspaces that can be used in the compiler environment of your choice.
The suite of CMake tools were created by Kitware in response to the need for a powerful, cross-platform build environment for open-source projects such as ITK and VTK.
- meson
一個構建工具，看關操作請見 makeXcmakeXmesonXgn
[PyPi] Meson is a cross-platform build system designed to be both as fast and as user friendly as possible. It supports many languages and compilers, including GCC, Clang, PGI, Intel, and Visual Studio. Its build definitions are written in a simple non-Turing complete DSL
- ninja
一個構建工具，看關操作請見 makeXcmakeXmesonXgn
[PyPi] Ninja is a small build system with a focus on speed.
不要試著升級，目前版本也不要超過 Python 3.10.16
pip install --upgrade pyproject-toml==0.0.12
pip install --upgrade pygobject==3.50
pip install --upgrade wheel==0.36.2
pip install --upgrade setuptools==58.5.3以下的解決方式不見得有效，試看看吧
II.1. g-ir-scanner ... distutils.errors.DistutilsExecError: command '-I/work/codebase/xbox/xbox_123/install/ubuntu/include' failed with exit status 1
網路上找不到合適的解決方式，不過 g-ir-scanner 非必須，先移除之。
$ g-ir-scanner --version
g-ir-scanner 1.64.1
$ sudo apt remove gobject-introspection
$ g-ir-scanner --version
Command 'g-ir-scanner' not found, but can be installed with:
$ sudo apt install gobject-introspection$ cd /usr/lib/x86_64-linux-gnu/gobject-introspection/giscanner
$ ll *.so
-rw-r--r-- 1 root root 102000 五 4 2020 _giscanner.cpython-38-x86_64-linux-gnu.so
$ sudo ln -s _giscanner.cpython-38-x86_64-linux-gnu.so _giscanner.so
$ sudo ldconfigII.2. ImportError: cannot import name 'six' from 'pkg_resources.extern' (/usr/lib/python3/dist-packages/pkg_resources/extern/init.py)
pip3 和 python3 版本要匹配。
$ pip3 --version
Traceback (most recent call last):
File "/usr/bin/pip3", line 6, in <module>
from pkg_resources import load_entry_point
File "/usr/lib/python3/dist-packages/pkg_resources/__init__.py", line 57, in <module>
from pkg_resources.extern import six
ImportError: cannot import name 'six' from 'pkg_resources.extern' (/usr/lib/python3/dist-packages/pkg_resources/extern/__init__.py)
此問題常發生在更換 python 版本時，只安裝了主體，其它套件忘了安裝
$ export PJ_PYTHON_VER=`python -c 'import sys; print("{0[0]}.{0[1]}".format(sys.version_info))'`
$ echo $PJ_PYTHON_VER
3.10
$ sudo apt install -y python${PJ_PYTHON_VER}-distutils此問題常發生在更換 python 版本時，只安裝了主體，其它套件忘了安裝
$ pip install --upgrade virtualenv
# or 有時 pip 無法順利安裝時
$ export PJ_PYTHON_VER=`python -c 'import sys; print("{0[0]}.{0[1]}".format(sys.version_info))'`
$ echo $PJ_PYTHON_VER
3.10
$ sudo apt install -y python${PJ_PYTHON_VER}-venv
$ virtualenv --version
virtualenv 20.26.1 from /home/lanka/.local/lib/python3.10/site-packages/virtualenv/__init__.pyII.5. ImportError: cannot import name 'html5lib' from 'pip._vendor' (/usr/lib/python3/dist-packages/pip/_vendor/init.py)
pip 和 python 的版本要達成一致
$ export PJ_PYTHON_VER=`python -c 'import sys; print("{0[0]}.{0[1]}".format(sys.version_info))'`
# 有時試著移除 ~/.local/lib/python${PJ_PYTHON_VER}
$ echo $PJ_PYTHON_VER
$ mv ~/.local/lib/python${PJ_PYTHON_VER} ~/.local/lib/python${PJ_PYTHON_VER}-bak
# reinstall pip
$ curl -sS https://bootstrap.pypa.io/get-pip.py | python${PJ_PYTHON_VER}
$ pip install cmake$ pip install ninjaII.8. DEPRECATION: dblatex 0.3.11py3 has a non-standard version number. pip 24.1 will enforce this behaviour change.
類似的問題常發生，dblatex 0.3.11py3 為特別版本；不見得要解決。
# for python3.8
$ sudo apt install -y python3-apt
$ cd /usr/lib/python3/dist-packages
$ ll apt*.so
-rw-r--r-- 1 root root 365464 三 14 2023 apt_inst.cpython-38d-x86_64-linux-gnu.so
-rw-r--r-- 1 root root 60080 三 14 2023 apt_inst.cpython-38-x86_64-linux-gnu.so
-rw-r--r-- 1 root root 3394768 三 14 2023 apt_pkg.cpython-38d-x86_64-linux-gnu.so
-rw-r--r-- 1 root root 359376 三 14 2023 apt_pkg.cpython-38-x86_64-linux-gnu.so
$ sudo ln -s apt_pkg.cpython-38d-x86_64-linux-gnu.so apt_pkg.so# for python3.10 and Ubuntu 20.04.6
$ lsb_release -a | grep Description
No LSB modules are available.
Description: Ubuntu 20.04.6 LTS
# https://launchpad.net/python-apt
# download python-apt_2.0.0ubuntu0.20.04.6.tar.xz
$ tar xvf python-apt_2.0.0ubuntu0.20.04.6.tar.xz
$ cd python-apt-2.0.0ubuntu0.20.04.6
$ sudo apt-get install libapt-pkg-dev
$ python setup.py build
$ cd build/lib.linux-x86_64-cpython-310
$ sudo cp *.so /usr/lib/python3/dist-packages# for python3.10
$ cd /usr/lib/python3/dist-packages/gi
$ pip3 install --upgrade pygobject
$ sudo cp ~/.local/lib/python${PJ_PYTHON_VER}/site-packages/gi/*.so /usr/lib/python3/dist-packages/gi# for python3.10 and Ubuntu 20.04.6
$ lsb_release -a | grep Description
No LSB modules are available.
Description: Ubuntu 20.04.6 LTS
# https://launchpad.net/ubuntu/+source/pygobject/
# https://launchpad.net/ubuntu/focal/+package/python-gi
# download pygobject_3.36.0.orig.tar.xz
# download pygobject_3.42.0.orig.tar.xz - for python3.12
$ tar xvf pygobject_3.36.0.orig.tar.xz
$ cd pygobject-3.36.0/
$ sudo apt-get install libgirepository1.0-dev libcairo2-dev
$ python setup.py build
$ cd build/lib.linux-x86_64-cpython-310/gi/
$ sudo cp *.so /usr/lib/python3/dist-packages/gi# https://launchpad.net/ubuntu/+source/cairo
# download cairo_1.18.2.orig.tar.xzII.11. dpkg: error processing archive /var/cache/apt/archives/python3.12_3.12.8-1+focal1_amd64.deb (--unpack)
$ sudo apt list --installed | grep 'python3.12' | cut -d'/' -f1 | xargs -o sudo apt autoremove && sudo apt install python3.12-fullsudo mv /usr/lib/python${PJ_PYTHON_VER}/EXTERNALLY-MANAGED /usr/lib/python${PJ_PYTHON_VER}/EXTERNALLY-MANAGED.old安裝新版 dblatex_0.3.12py3-2_all.deb
$ sudo dpkg -i dblatex_0.3.12py3-2_all.deb$ sudo apt-get install python3.13-dev$ virtualenv --help
usage: virtualenv [--version] [--with-traceback] [-v | -q] [--read-only-app-data] [--app-data APP_DATA] [--reset-app-data] [--upgrade-embed-wheels] [--discovery {builtin}] [-p py] [--try-first-with py_exe]
[--creator {builtin,cpython3-posix,venv}] [--seeder {app-data,pip}] [--no-seed] [--activators comma_sep_list] [--clear] [--no-vcs-ignore] [--system-site-packages] [--symlinks | --copies] [--no-download | --download]
[--extra-search-dir d [d ...]] [--pip version] [--setuptools version] [--wheel version] [--no-pip] [--no-setuptools] [--no-wheel] [--no-periodic-update] [--symlink-app-data] [--prompt prompt] [-h]
dest
optional arguments:
--version display the version of the virtualenv package and its location, then exit
--with-traceback on failure also display the stacktrace internals of virtualenv (default: False)
--read-only-app-data use app data folder in read-only mode (write operations will fail with error) (default: False)
--app-data APP_DATA a data folder used as cache by the virtualenv (default: /home/lanka/.local/share/virtualenv)
--reset-app-data start with empty app data folder (default: False)
--upgrade-embed-wheels trigger a manual update of the embedded wheels (default: False)
-h, --help show this help message and exit
verbosity:
verbosity = verbose - quiet, default INFO, mapping => CRITICAL=0, ERROR=1, WARNING=2, INFO=3, DEBUG=4, NOTSET=5
-v, --verbose increase verbosity (default: 2)
-q, --quiet decrease verbosity (default: 0)
discovery:
discover and provide a target interpreter
--discovery {builtin} interpreter discovery method (default: builtin)
-p py, --python py interpreter based on what to create environment (path/identifier) - by default use the interpreter where the tool is installed - first found wins (default: [])
--try-first-with py_exe try first these interpreters before starting the discovery (default: [])
creator:
options for creator builtin
--creator {builtin,cpython3-posix,venv}
create environment via (builtin = cpython3-posix) (default: builtin)
dest directory to create virtualenv at
--clear remove the destination directory if exist before starting (will overwrite files otherwise) (default: False)
--no-vcs-ignore don't create VCS ignore directive in the destination directory (default: False)
--system-site-packages give the virtual environment access to the system site-packages dir (default: False)
--symlinks try to use symlinks rather than copies, when symlinks are not the default for the platform (default: True)
--copies, --always-copy try to use copies rather than symlinks, even when symlinks are the default for the platform (default: False)
seeder:
options for seeder app-data
--seeder {app-data,pip} seed packages install method (default: app-data)
--no-seed, --without-pip do not install seed packages (default: False)
--no-download, --never-download
pass to disable download of the latest pip/setuptools/wheel from PyPI (default: True)
--download pass to enable download of the latest pip/setuptools/wheel from PyPI (default: False)
--extra-search-dir d [d ...] a path containing wheels to extend the internal wheel list (can be set 1+ times) (default: [])
--pip version version of pip to install as seed: embed, bundle, none or exact version (default: bundle)
--setuptools version version of setuptools to install as seed: embed, bundle, none or exact version (default: bundle)
--wheel version version of wheel to install as seed: embed, bundle, none or exact version (default: bundle)
--no-pip do not install pip (default: False)
--no-setuptools do not install setuptools (default: False)
--no-wheel do not install wheel (default: False)
--no-periodic-update disable the periodic (once every 14 days) update of the embedded wheels (default: False)
--symlink-app-data symlink the python packages from the app-data folder (requires seed pip>=19.3) (default: False)
activators:
options for activation scripts
--activators comma_sep_list activators to generate - default is all supported (default: bash,cshell,fish,nushell,powershell,python)
--prompt prompt provides an alternative prompt prefix for this environment (value of . means name of the current working directory) (default: None)
config file /home/lanka/.config/virtualenv/virtualenv.ini missing (change via env var VIRTUALENV_CONFIG_FILE)
$ update-alternatives --help
Usage: update-alternatives [<option> ...] <command>
Commands:
--install <link> <name> <path> <priority>
[--slave <link> <name> <path>] ...
add a group of alternatives to the system.
--remove <name> <path> remove <path> from the <name> group alternative.
--remove-all <name> remove <name> group from the alternatives system.
--auto <name> switch the master link <name> to automatic mode.
--display <name> display information about the <name> group.
--query <name> machine parseable version of --display <name>.
--list <name> display all targets of the <name> group.
--get-selections list master alternative names and their status.
--set-selections read alternative status from standard input.
--config <name> show alternatives for the <name> group and ask the
user to select which one to use.
--set <name> <path> set <path> as alternative for <name>.
--all call --config on all alternatives.
<link> is the symlink pointing to /etc/alternatives/<name>.
(e.g. /usr/bin/pager)
<name> is the master name for this link group.
(e.g. pager)
<path> is the location of one of the alternative target files.
(e.g. /usr/bin/less)
<priority> is an integer; options with higher numbers have higher priority in
automatic mode.
Options:
--altdir <directory> change the alternatives directory.
--admindir <directory> change the administrative directory.
--log <file> change the log file.
--force allow replacing files with alternative links.
--skip-auto skip prompt for alternatives correctly configured
in automatic mode (relevant for --config only)
--quiet quiet operation, minimal output.
--verbose verbose operation, more output.
--debug debug output, way more output.
--help show this help message.
--version show the version.
$ pip3 --help
Usage:
pip3 <command> [options]
Commands:
install Install packages.
download Download packages.
uninstall Uninstall packages.
freeze Output installed packages in requirements format.
list List installed packages.
show Show information about installed packages.
check Verify installed packages have compatible dependencies.
config Manage local and global configuration.
search Search PyPI for packages.
wheel Build wheels from your requirements.
hash Compute hashes of package archives.
completion A helper command used for command completion.
debug Show information useful for debugging.
help Show help for commands.
General Options:
-h, --help Show help.
--isolated Run pip in an isolated mode, ignoring environment variables and user configuration.
-v, --verbose Give more output. Option is additive, and can be used up to 3 times.
-V, --version Show version and exit.
-q, --quiet Give less output. Option is additive, and can be used up to 3 times (corresponding to WARNING, ERROR, and CRITICAL logging levels).
--log <path> Path to a verbose appending log.
--proxy <proxy> Specify a proxy in the form [user:passwd@]proxy.server:port.
--retries <retries> Maximum number of retries each connection should attempt (default 5 times).
--timeout <sec> Set the socket timeout (default 15 seconds).
--exists-action <action> Default action when a path already exists: (s)witch, (i)gnore, (w)ipe, (b)ackup, (a)bort.
--trusted-host <hostname> Mark this host or host:port pair as trusted, even though it does not have valid or any HTTPS.
--cert <path> Path to alternate CA bundle.
--client-cert <path> Path to SSL client certificate, a single file containing the private key and the certificate in PEM format.
--cache-dir <dir> Store the cache data in <dir>.
--no-cache-dir Disable the cache.
--disable-pip-version-check
Don't periodically check PyPI to determine whether a new version of pip is available for download. Implied with --no-index.
--no-color Suppress colored output
--no-python-version-warning
Silence deprecation warnings for upcoming unsupported Pythons.
Created and designed by Lanka Hsu.
HelperX is available under the BSD-3-Clause license. See the LICENSE file for more info.