poetry shell is also not a term emulator, it's just a subshell with some environment variables setup for your project. Once you are in, it's just a regular shell. If anything is slow, it's where you add or remove a dependency, but it's probably faster than you editing requirements.txt, clearing out your virtualenv and then reinstalling everything again.
The process spawned by `poetry shell` is a terminal emulator driven by the pexpect and cleo packages. It hijacks and proxies the user's keystrokes before sending them to the underlying terminal.
That is the point I was making. It's not a proper terminal emulator, instead it's a half-assed one. If it gets between the user's keystrokes and the host shell, it should be a proper emulator. Otherwise it should set up the environment and get out of the way.
poetry shell is also not a term emulator, it's just a subshell with some environment variables setup for your project. Once you are in, it's just a regular shell. If anything is slow, it's where you add or remove a dependency, but it's probably faster than you editing requirements.txt, clearing out your virtualenv and then reinstalling everything again.