升级到Ubuntu20.04.pip

Question

我从19.10升级到Ubuntu 20.04，现在我不能使用pip。

zeno:~$ pip --version

Command 'pip' not found, but there are 18 similar ones.

Python已安装：

zeno:~$ python3 --version
Python 3.8.2

但如果我试着检查pip，我会得到：

    zeno:~/Desktop/tetris$ sudo apt install python3-pip
    Reading package lists... Done
    Building dependency tree       
    Reading state information... Done
    python3-pip is already the newest version (20.0.2-5ubuntu1).
    The following packages were automatically installed and are no longer required:
     dh-python elpa-async enchant gedit-plugin-zeitgeist gir1.2-mutter-5
     gnome-software-common libappstream-glib8 libapt-pkg5.90
     libboost-date-time1.67.0 libboost-iostreams1.67.0 libbrlapi0.6
     libcodec2-0.8.1 libcroco3 libdns-export1104 libdns1104 libdvdread4
     libegl1-mesa libenchant1c2a libept1.5.90 libevent-2.1-6 libexiv2-14
     libfprint0 libgeoip1 libgit2-27 libglvnd-core-dev libgnome-desktop-3-18
     libgspell-1-1 libgutenprint-common libgutenprint9 libgweather-3-15 libicu63
     libiptc0 libisc-export1100 libisc1100 libisc1105 libisl21 liblivemedia64
     liblouis17 liblwres161 libmicrodns0 libmozjs-60-0 libmutter-5-0 libmysofa0
     libnettle6 liboauth0 libperl5.28 libplymouth4 libpoppler90
     libpython3.7-minimal libqpdf21 libsnmp30 libusbmuxd4 libx11-xcb-dev
     libx265-176 libxcb-dri2-0-dev libxcb-dri3-dev libxcb-shape0-dev
     libxcb-sync-dev libxcb-xfixes0-dev libxshmfence-dev libzeitgeist-2.0-0
     perl-modules-5.28 printer-driver-gutenprint python-gobject-2
     python3-asn1crypto python3-pypdf2 python3.7-minimal ubuntu-system-service
     x11proto-composite-dev x11proto-fixes-dev
   Use 'sudo apt autoremove' to remove them.
   0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.

我迷路了。谢谢你的帮助

使现代化

我使用venv创建虚拟环境。当没有激活venv时，我可以使用pip3：

zeno:~/Desktop/tetris$ pip3 -V
pip 20.0.2 from /usr/lib/python3/dist-packages/pip (python 3.8)

但是如果我激活一个venv，它就不起作用了：

(.tetris) zeno:~/Desktop/tetris$ pip3
Traceback (most recent call last):
  File "/home/zeno/Desktop/tetris/.tetris/bin/pip3", line 6, in <module>
    from pip._internal import main
ModuleNotFoundError: No module named 'pip'

感谢您的建议和持续的帮助。

使现代化

我尝试删除venv并创建一个新的venv，但似乎我需要pip工作才能做到这一点：

zeno:~/Desktop/tetris$ python3 -m venv .tetris

给予：

The virtual environment was not created successfully because ensurepip is not
available.  On Debian/Ubuntu systems, you need to install the python3-venv
package using the following command.

    apt-get install python3-venv

You may need to use sudo with that command.  After installing the python3-venv
package, recreate your virtual environment.

Failing command: ['/home/zeno/Desktop/tetris/.tetris/bin/python3', '-Im', 'ensurepip', '--upgrade', '--default-pip']

Answer 1

最适合我的解决方案是dobairoland在esp idf github（第4474期）上给出的，如Espressif文档中所示：

sudo apt-get install python3 python3-pip python3-setuptools

sudo update-alternatives --install /usr/bin/python python /usr/bin/python3 10

备选方案（1）：起初，我可以使用第三方bash安装脚本的别名来解决这个问题，该脚本是用pip硬编码的（前面提到的安装/重新安装都不适用于我），因此这也可以是一个选项：

sudo apt-get install python3-pip
alias pip="pip3"

这个（公认不太优雅的选项）可能对脚本有帮助：

if [ "$(cat /etc/os-release | grep VERSION_ID)" == 'VERSION_ID="20.04"' ]; then
 alias pip="pip3"
else 
  echo "no pip alias"
fi

备选方案（2）还有一种黑客技术在技术上对我有效，但将不推荐的软件强制安装到系统上可能不是一个好主意：

wget https://bootstrap.pypa.io/get-pip.py
sudo python2.7 get-pip.py

Answer 2

我不得不清除python3-venv并重新安装它：

zeno:~$ sudo apt purge python3-venv

然后

zeno:~$ sudo apt install python3-venv

谢谢大家

Answer 3

有时在操作系统升级后，您需要重新安装软件包。尝试：

sudo apt install --reinstall python3-pip