欧博How can I install Python 3.9 from the Anaconda p
Python 3.9 is available for download via conda on the conda-forge channel as of October 9, 2020. See the Python notes and the conda-forge/python site.
(Copying my comment on the OP's post) A python 3.9 release candidate was released today, and the 3.9.0 release is . It seems that both the anaconda and conda-forge channels do not have python release candidates. Compiled Python packages (e.g., numpy) would also need to be built with 3.9, and those also seem to not be available.
If you look at https://anaconda.org/conda-forge/python, there are several labels available, but none of them includes Python 3.9. The commands
conda install -c conda-forge/label/dev python conda install -c conda-forge/label/prerelease pythonboth install Python 3.8 for me on amd64 Linux.
The anaconda channel also does not include Python 3.9. You can look in the version dropdown in the "Files" tab. At the time of writing, the latest version is 3.8.5.