EDIT: Please try to keep the conversation in one thread. Anyway, if installing meson via pip succeeds, but you still can't access the executable, you'll have to set up your PATH environment variable to include whatever path pip installs binaries to. I don't know how this is done, as I don't personally have access to an instance of macos where homebrew / pip didn't work out of the box; you'll have to consult their manuals.
I actully install meson because i follow every step and it give me no error except instead of uisng pip command to install,I use pip3 command which result in success. (i duplicate the thread since i don't see the original thread i created)
Oh okay, I though pip ran but didn't add meson to your path, in response to which you tried pip3, which ran and did add meson to your path. That's not a solution then .-. What I said in the first response applies then, you'll have to solve this on your own. The guide assumes that macos has python 3 installed out of the box and installing pip on it adds it to the path, but these assumptions clearly don't hold in your case.
I'm sure it's possible, but like I said, you're in a better position to test than I am, so you'll have to figure it out yourself. I'm sure it'd be easier to figure out why pip doesn't install binaries somewhere where bash sees them than deal with Visual Studio's stupidity.