{ lib, stdenv, callPackage, pythonPackagesExtensions, config
, makeScopeWithSplicing', ... }:

{ implementation, libPrefix, executable, sourceVersion, pythonVersion
, packageOverrides, sitePackages, hasDistutilsCxxPatch, pythonOnBuildForBuild
, pythonOnBuildForHost, pythonOnBuildForTarget, pythonOnHostForHost
, pythonOnTargetForTarget, pythonAttr ? null, self # is pythonOnHostForTarget
}:
let
  pythonPackages = let
    ensurePythonModules = items:
      let
        exceptions = [ stdenv ];
        providesSetupHook = lib.attrByPath [ "provides" "setupHook" ] false;
        valid = value:
          pythonPackages.hasPythonModule value || providesSetupHook value
          || lib.elem value exceptions;
        func = name: value:
          if lib.isDerivation value then
            lib.extendDerivation (valid value || throw
              "${name} should use `buildPythonPackage` or `toPythonModule` if it is to be part of the Python packages set.")
            { } value
          else
            value;
      in lib.mapAttrs func items;
  in ensurePythonModules (callPackage
    # Function that when called
    # - imports python-packages.nix
    # - adds spliced package sets to the package set
    # - applies overrides from `packageOverrides` and `pythonPackagesOverlays`.
    ({ pkgs, stdenv, python, overrides }:
      let
        pythonPackagesFun = import ./python-packages-base.nix {
          inherit stdenv pkgs lib;
          python = self;
        };
        otherSplices = {
          selfBuildBuild = pythonOnBuildForBuild.pkgs;
          selfBuildHost = pythonOnBuildForHost.pkgs;
          selfBuildTarget = pythonOnBuildForTarget.pkgs;
          selfHostHost = pythonOnHostForHost.pkgs;
          selfTargetTarget =
            pythonOnTargetForTarget.pkgs or { }; # There is no Python TargetTarget.
        };
        hooks = import ./hooks/default.nix;
        keep = self: hooks self { };
        optionalExtensions = cond: as: lib.optionals cond as;
        pythonExtension = import ../../../top-level/python-packages.nix;
        python2Extension = import ../../../top-level/python2-packages.nix;
        extensions = lib.composeManyExtensions ([ hooks pythonExtension ]
          ++ (optionalExtensions (!self.isPy3k) [ python2Extension ])
          ++ pythonPackagesExtensions ++ [ overrides ]);
        aliases = self: super:
          lib.optionalAttrs config.allowAliases
          (import ../../../top-level/python-aliases.nix lib self super);
      in makeScopeWithSplicing' {
        inherit otherSplices keep;
        f = lib.extends (lib.composeExtensions aliases extensions)
          pythonPackagesFun;
      }) {
        overrides = packageOverrides;
        python = self;
      });
  pythonOnBuildForHost_overridden = pythonOnBuildForHost.override {
    inherit packageOverrides;
    self = pythonOnBuildForHost_overridden;
  };
in rec {
  isPy27 = pythonVersion == "2.7";
  isPy37 = pythonVersion == "3.7";
  isPy38 = pythonVersion == "3.8";
  isPy39 = pythonVersion == "3.9";
  isPy310 = pythonVersion == "3.10";
  isPy311 = pythonVersion == "3.11";
  isPy312 = pythonVersion == "3.12";
  isPy2 = lib.strings.substring 0 1 pythonVersion == "2";
  isPy3 = lib.strings.substring 0 1 pythonVersion == "3";
  isPy3k = isPy3;
  isPyPy = lib.hasInfix "pypy" interpreter;

  buildEnv = callPackage ./wrapper.nix {
    python = self;
    inherit (pythonPackages) requiredPythonModules;
  };
  withPackages =
    import ./with-packages.nix { inherit buildEnv pythonPackages; };
  pkgs = pythonPackages;
  interpreter = "${self}/bin/${executable}";
  inherit executable implementation libPrefix pythonVersion sitePackages;
  inherit sourceVersion;
  pythonAtLeast = lib.versionAtLeast pythonVersion;
  pythonOlder = lib.versionOlder pythonVersion;
  inherit hasDistutilsCxxPatch;
  # Remove after 24.11 is released.
  pythonForBuild = lib.warnIf (lib.isInOldestRelease 2311)
    "`pythonForBuild` (from `python*`) has been renamed to `pythonOnBuildForHost`"
    pythonOnBuildForHost_overridden;
  pythonOnBuildForHost = pythonOnBuildForHost_overridden;

  tests = callPackage ./tests.nix { python = self; };

  inherit pythonAttr;
}