问题：我可以强迫pip重新安装当前版本吗？
我遇到过以下情况：当前版本的软件包似乎无法正常工作，需要重新安装。但是，pip install -U不要触摸已经是最新的软件包。我看到了如何通过先卸载（使用pip uninstall）然后安装来强制进行重新安装，但是有没有办法在一个步骤中简单地将“更新”强制为名义上的当前版本？
I’ve come across situations where a current version of a package seems not to be working and requires reinstallation. But pip install -U won’t touch a package that is already up-to-date. I see how to force a reinstallation by first uninstalling (with pip uninstall) and then installing, but is there a way to simply force an “update” to a nominally current version in a single step?
回答 0
pip install --upgrade --force-reinstall <package>
升级时，请重新安装所有软件包，即使它们已经是最新的。
pip install -I <package>
pip install --ignore-installed <package>
忽略已安装的软件包（改为重新安装）。
pip install --upgrade --force-reinstall <package>
When upgrading, reinstall all packages even if they are already up-to-date.
pip install -I <package>
pip install --ignore-installed <package>
Ignore the installed packages (reinstalling instead).
回答 1
您可能希望拥有所有三个选项：--upgrade并--force-reinstall确保重新安装，同时--no-deps避免重新安装依赖项。
$ sudo pip install --upgrade --no-deps --force-reinstall <packagename>
否则，您可能会遇到pip开始重新编译Numpy或其他大型软件包的问题。
You might want to have all three options: --upgrade and --force-reinstall ensures reinstallation, while --no-deps avoids reinstalling dependencies.
$ sudo pip install --upgrade --no-deps --force-reinstall <packagename>
Otherwise you might run into the problem that pip starts to recompile Numpy or other large packages.
回答 2
如果要重新安装Requirements.txt文件中指定的软件包而不进行升级，那么只需重新安装Requirements.txt文件中指定的特定版本：
pip install -r requirements.txt --ignore-installed
If you want to reinstall packages specified in a requirements.txt file, without upgrading, so just reinstall the specific versions specified in the requirements.txt file:
pip install -r requirements.txt --ignore-installed
回答 3
--force-reinstall
似乎没有强制使用python2.7和pip-1.5重新安装
我不得不用
--no-deps --ignore-installed
--force-reinstall
doesn’t appear to force reinstall using python2.7 with pip-1.5
I’ve had to use
--no-deps --ignore-installed
回答 4
如果您的文本文件包含大量软件包，则需要添加-r标志
pip install --upgrade --no-deps --force-reinstall -r requirements.txt
If you have a text file with loads of packages you need to add the -r flag
pip install --upgrade --no-deps --force-reinstall -r requirements.txt
回答 5
如果您需要强制重新安装pip本身，则可以执行以下操作：
python -m pip install --upgrade --force-reinstall pip
In the case you need to force the reinstallation of pip itself you can do:
python -m pip install --upgrade --force-reinstall pip
回答 6
sudo pip3 install --upgrade --force-reinstall --no-deps --no-cache-dir <package-name>==<package-version>
一些相关的答案：
点安装选项“忽略安装”和“强制重新安装”之间的区别
