Formula installs python version it depends on, but six package with the same code does not

[Oleksii-Svintsitskyi]

Why when I'm creating my own formula without any additional resources and use

depends_on "python@3.10" => [:build, :test] 
depends_on "python@3.8" => [:build, :test]
depends_on "python@3.9" => [:build, :test]

def pythons
  deps.map(&:to_formula).sort_by(&:version)
end
  
def install
  pythons.each do |python|
    python_exe = python.opt_libexec/"bin/python"
    system python_exe, *Language::Python.setup_install_args(prefix, python)
end

just like in six package, my Formula installs all the python versions that is depends on?

And when I'm install six package, it just installs the package for all the pythons (3.8, 3.9, 3.10) that are already installed, but not installs pythons itself?

[SMillerDev]

It'll only install those pythons if you build from source

[Oleksii-Svintsitskyi]

@SMillerDev Do you mean brew install --build-from-source <package>?
If yes, than it's not true in this situation, because I'm just running brew install <package>

[Oleksii-Svintsitskyi]

@SMillerDev or it has something to do with the bottle section?

[SMillerDev]

If there are no prebuilt binaries it'll build from source.

[Oleksii-Svintsitskyi]

@SMillerDev thank you!