Mac Monterey系统下用Anaconda创建Python2.7环境失败求助

问题重现 #

执行命令：

conda create -n python2 python=2.7 anaconda

出现报错：

Collecting package metadata (current_repodata.json): done
Solving environment: unsuccessful attempt using repodata from current_repodata.json, retrying with next repodata source.
Collecting package metadata (repodata.json): | WARNING conda.models.version:get_matcher(556): Using .* with relational operator is superfluous and deprecated and will be removed in a future version of conda. Your spec was 1.8.0.*, but conda is ignoring the .* and treating it as 1.8.0
WARNING conda.models.version:get_matcher(556): Using .* with relational operator is superfluous and deprecated and will be removed in a future version of conda. Your spec was 1.9.0.*, but conda is ignoring the .* and treating it as 1.9.0
done
Solving environment: failed

PackagesNotFoundError: The following packages are not available from current channels:

  - python=2.7

原因 #

Python2.7已停止官方维护，conda默认的defaults频道已移除相关包；如果是Apple Silicon（M系列芯片）Mac，还存在Python2.7无原生arm64编译包的问题。

解决方案 #

1. 针对Apple Silicon用户：切换到x86终端

打开终端，先执行以下命令切换到x86架构的shell（利用Rosetta2兼容）：

arch -x86_64 zsh

（如果用bash，替换成arch -x86_64 bash）

2. 指定conda-forge频道创建环境

conda-forge频道仍保留Python2.7的兼容包，执行以下命令：

conda create -n python2 python=2.7 anaconda -c conda-forge

3. 若上述命令仍失败：精简环境后手动装包

如果安装整个anaconda元包失败，先创建仅含Python2.7的基础环境：

conda create -n python2 python=2.7 -c conda-forge

激活环境后按需安装需要的包，比如：

conda activate python2
conda install numpy pandas matplotlib -c conda-forge

内容的提问来源于stack exchange，提问作者Antonio.Aubry