Function install_python_stack

studio/install_python_stack.py:1995–2391

()

def install_python_stack() -> int:
    global USE_UV, _STEP, _TOTAL
    _STEP = 0

    # install.sh (which already installed unsloth) sets SKIP_STUDIO_BASE=1 to
    # avoid reinstalling base packages. "unsloth studio update" does NOT set it,
    # so base packages (unsloth + unsloth-zoo) are reinstalled to pick up new
    # versions.
    skip_base = os.environ.get("SKIP_STUDIO_BASE", "0") == "1"
    # --package installs a different package name (for testing).
    package_name = os.environ.get("STUDIO_PACKAGE_NAME", "unsloth")
    # --local overlays a local repo checkout after updating deps.
    local_repo = os.environ.get("STUDIO_LOCAL_REPO", "")
    base_total = 11 if IS_WINDOWS else 12  # +1 for the anyio repair check (step 8b)
    if IS_MACOS:
        base_total -= 1  # triton step is skipped on macOS
    if not IS_MACOS and not NO_TORCH:
        base_total += 1  # ROCm torch check (line 1526) -- all non-macOS platforms
        if not IS_WINDOWS:
            base_total += 2  # flash-attn (line 1620) + ROCm torch final (line 1705) -- Linux only
    _TOTAL = (base_total - 1) if skip_base else base_total

    # 1. Try uv for faster installs (before pip upgrade -- uv venvs don't
    #    include pip by default).
    USE_UV = _bootstrap_uv()

    # 2. Ensure pip is available (uv venvs from install.sh omit pip).
    _progress("pip bootstrap")
    if USE_UV:
        run(
            "Bootstrapping pip via uv",
            [
                "uv",
                "pip",
                "install",
                "--python",
                sys.executable,
                "pip",
            ],
        )
    else:
        # pip may not exist yet (uv-created venvs omit it). Try ensurepip,
        # then upgrade. Direct upgrade only when pip is already present.
        _has_pip = (
            subprocess.run(
                [sys.executable, "-m", "pip", "--version"],
                stdout = subprocess.DEVNULL,
                stderr = subprocess.DEVNULL,
                **_windows_hidden_subprocess_kwargs(),
            ).returncode
            == 0
        )

        if not _has_pip:
            run(
                "Bootstrapping pip via ensurepip",
                [sys.executable, "-m", "ensurepip", "--upgrade"],
            )