Pip and other aliases in Mac Catalina / ZSH

Mac Catalina uses ZSH by default. Which is what you'll get if you buy a new Mac.
If you follow the guide, https://docs.python-guide.org/starting/install3/osx/#pipenv-virtual-environments, at the end, if you just run "pip" in your terminal, it will not be found.

After I changed the default terminal to bash, and reinstalled python with brew, then running "pip --version" gives pip version 3 as expected.

从链接的 Python Guide URL 中 macOS 的 pipenv 虚拟环境部分开始，并在 Catalina 的默认 ZSH shell 中重现文档中的命令。检查报告中的 pip 命令以及它与 Bash 和 Homebrew 的差异；完成标准是该指南解释或解决新 macOS 用户缺少 pip 别名的问题。