Thank you Donald.
I’ve solved the problem (Error with "dwi2response") by the command below.
------------ How can I still add executable files to my path?
Local customizations, such as what you’re doing, belong in /usr/local instead. The path /usr/local/bin doesn’t exist by default, but you can create it and put custom binaries (and symlinks) in it:
sudo mkdir -p /usr/local/bin
sudo ln -s /my_python3_path /usr/local/bin/python