ERROR: pip‘s dependency resolver does not currently take into account all the packages 解决办法分享

一、问题

我的问题是用pip安装包（ pip install --upgrade setuptools）的时候出现问题：ERROR: pip's dependency resolver does not currently take into account all the packages that are installed. This behaviour is the source of the following dependency conflicts.

spyder 5.1.5 requires pyqt5<5.13, which is not installed.

spyder 5.1.5 requires pyqtwebengine<5.13, which is not installed.

conda-repo-cli 1.0.4 requires pathlib, which is not installed.

anaconda-project 0.10.2 requires ruamel-yaml, which is not installed.

从问题提示来看，就是pip 的依赖项解析器当前未考虑安装的所有包。此行为是以下依赖项冲突的根源。

二、解决办法

我就根据错误提示，分别重新安装了以上四个版本要求的包，不再截图，把代码附上：

pip install -i https://pypi.tuna.tsinghua.edu.cn/simple  " pyqt5<5.13"
pip install -i https://pypi.tuna.tsinghua.edu.cn/simple  " pyqtwebengine<5.13"
pip install -i https://pypi.tuna.tsinghua.edu.cn/simple  pathlib
pip install -i https://pypi.tuna.tsinghua.edu.cn/simple   ruamel-yaml

然后就没有报错了。