diff --git a/Formula/python@3.9.rb b/Formula/python@3.9.rb
new file mode 100644
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+++ b/Formula/python@3.9.rb
@@ -0,0 +1,320 @@
+class PythonAT39 < Formula
+  desc "Interpreted, interactive, object-oriented programming language"
+  homepage "https://www.python.org/"
+  url "https://www.python.org/ftp/python/3.9.0/Python-3.9.0.tar.xz"
+  sha256 "9c73e63c99855709b9be0b3cc9e5b072cb60f37311e8c4e50f15576a0bf82854"
+  license "Python-2.0"
+
+  livecheck do
+    url "https://www.python.org/ftp/python/"
+    regex(%r{href=.*?v?(3\.9(?:\.\d+)*)/?["' >]}i)
+  end
+
+  # setuptools remembers the build flags python is built with and uses them to
+  # build packages later. Xcode-only systems need different flags.
+  pour_bottle? do
+    reason <<~EOS
+      The bottle needs the Apple Command Line Tools to be installed.
+        You can install them, if desired, with:
+          xcode-select --install
+    EOS
+    satisfy { MacOS::CLT.installed? }
+  end
+
+  keg_only :versioned_formula
+
+  depends_on "pkg-config" => :build
+  depends_on "gdbm"
+  depends_on "openssl@1.1"
+  depends_on "readline"
+  depends_on "sqlite"
+  depends_on "xz"
+
+  uses_from_macos "bzip2"
+  uses_from_macos "libffi"
+  uses_from_macos "ncurses"
+  uses_from_macos "unzip"
+  uses_from_macos "zlib"
+
+  skip_clean "bin/pip3", "bin/pip-3.4", "bin/pip-3.5", "bin/pip-3.6",
+             "bin/pip-3.7", "bin/pip-3.8", "bin/pip-3.9"
+  skip_clean "bin/easy_install3", "bin/easy_install-3.4", "bin/easy_install-3.5", "bin/easy_install-3.6",
+             "bin/easy_install-3.7", "bin/easy_install-3.8", "bin/easy_install-3.9"
+
+  resource "setuptools" do
+    url "https://files.pythonhosted.org/packages/7c/1b/9b68465658cda69f33c31c4dbd511ac5648835680ea8de87ce05c81f95bf/setuptools-50.3.0.zip"
+    sha256 "39060a59d91cf5cf403fa3bacbb52df4205a8c3585e0b9ba4b30e0e19d4c4b18"
+  end
+
+  resource "pip" do
+    url "https://files.pythonhosted.org/packages/59/64/4718738ffbc22d98b5223dbd6c5bb87c476d83a4c71719402935170064c7/pip-20.2.3.tar.gz"
+    sha256 "30c70b6179711a7c4cf76da89e8a0f5282279dfb0278bec7b94134be92543b6d"
+  end
+
+  resource "wheel" do
+    url "https://files.pythonhosted.org/packages/83/72/611c121b6bd15479cb62f1a425b2e3372e121b324228df28e64cc28b01c2/wheel-0.35.1.tar.gz"
+    sha256 "99a22d87add3f634ff917310a3d87e499f19e663413a52eb9232c447aa646c9f"
+  end
+
+  def install
+    # Unset these so that installing pip and setuptools puts them where we want
+    # and not into some other Python the user has installed.
+    ENV["PYTHONHOME"] = nil
+    ENV["PYTHONPATH"] = nil
+
+    xy = (buildpath/"configure.ac").read.slice(/PYTHON_VERSION, (3\.\d)/, 1)
+    lib_cellar = prefix/"Frameworks/Python.framework/Versions/#{xy}/lib/python#{xy}"
+
+    args = %W[
+      --prefix=#{prefix}
+      --enable-ipv6
+      --datarootdir=#{share}
+      --datadir=#{share}
+      --enable-framework=#{frameworks}
+      --enable-loadable-sqlite-extensions
+      --without-ensurepip
+      --with-dtrace
+      --with-openssl=#{Formula["openssl@1.1"].opt_prefix}
+    ]
+
+    cflags   = []
+    ldflags  = []
+    cppflags = []
+
+    if MacOS.sdk_path_if_needed
+      # Help Python's build system (setuptools/pip) to build things on SDK-based systems
+      # The setup.py looks at "-isysroot" to get the sysroot (and not at --sysroot)
+      cflags  << "-isysroot #{MacOS.sdk_path}" << "-I#{MacOS.sdk_path}/usr/include"
+      ldflags << "-isysroot #{MacOS.sdk_path}"
+      # For the Xlib.h, Python needs this header dir with the system Tk
+      # Yep, this needs the absolute path where zlib needed a path relative
+      # to the SDK.
+      cflags << "-I#{MacOS.sdk_path}/System/Library/Frameworks/Tk.framework/Versions/8.5/Headers"
+    end
+    # Avoid linking to libgcc https://mail.python.org/pipermail/python-dev/2012-February/116205.html
+    args << "MACOSX_DEPLOYMENT_TARGET=#{MacOS.version}"
+
+    # We want our readline! This is just to outsmart the detection code,
+    # superenv makes cc always find includes/libs!
+    inreplace "setup.py",
+      "do_readline = self.compiler.find_library_file(self.lib_dirs, 'readline')",
+      "do_readline = '#{Formula["readline"].opt_lib}/libhistory.dylib'"
+
+    inreplace "setup.py" do |s|
+      s.gsub! "sqlite_setup_debug = False", "sqlite_setup_debug = True"
+      s.gsub! "for d_ in self.inc_dirs + sqlite_inc_paths:",
+              "for d_ in ['#{Formula["sqlite"].opt_include}']:"
+    end
+
+    # Allow python modules to use ctypes.find_library to find homebrew's stuff
+    # even if homebrew is not a /usr/local/lib. Try this with:
+    # `brew install enchant && pip install pyenchant`
+    inreplace "./Lib/ctypes/macholib/dyld.py" do |f|
+      f.gsub! "DEFAULT_LIBRARY_FALLBACK = [", "DEFAULT_LIBRARY_FALLBACK = [ '#{HOMEBREW_PREFIX}/lib',"
+      f.gsub! "DEFAULT_FRAMEWORK_FALLBACK = [", "DEFAULT_FRAMEWORK_FALLBACK = [ '#{HOMEBREW_PREFIX}/Frameworks',"
+    end
+
+    args << "CFLAGS=#{cflags.join(" ")}" unless cflags.empty?
+    args << "LDFLAGS=#{ldflags.join(" ")}" unless ldflags.empty?
+    args << "CPPFLAGS=#{cppflags.join(" ")}" unless cppflags.empty?
+
+    system "./configure", *args
+    system "make"
+
+    ENV.deparallelize do
+      # Tell Python not to install into /Applications (default for framework builds)
+      system "make", "install", "PYTHONAPPSDIR=#{prefix}"
+      system "make", "frameworkinstallextras", "PYTHONAPPSDIR=#{pkgshare}"
+    end
+
+    # Any .app get a " 3" attached, so it does not conflict with python 2.x.
+    Dir.glob("#{prefix}/*.app") { |app| mv app, app.sub(/\.app$/, " 3.app") }
+
+    # Prevent third-party packages from building against fragile Cellar paths
+    inreplace Dir[lib_cellar/"**/_sysconfigdata__darwin_darwin.py",
+                  lib_cellar/"config*/Makefile",
+                  frameworks/"Python.framework/Versions/3*/lib/pkgconfig/python-3.?.pc"],
+              prefix, opt_prefix
+
+    # Help third-party packages find the Python framework
+    inreplace Dir[lib_cellar/"config*/Makefile"],
+              /^LINKFORSHARED=(.*)PYTHONFRAMEWORKDIR(.*)/,
+              "LINKFORSHARED=\\1PYTHONFRAMEWORKINSTALLDIR\\2"
+
+    # Fix for https://github.com/Homebrew/homebrew-core/issues/21212
+    inreplace Dir[lib_cellar/"**/_sysconfigdata__darwin_darwin.py"],
+              %r{('LINKFORSHARED': .*?)'(Python.framework/Versions/3.\d+/Python)'}m,
+              "\\1'#{opt_prefix}/Frameworks/\\2'"
+
+    # Symlink the pkgconfig files into HOMEBREW_PREFIX so they're accessible.
+    (lib/"pkgconfig").install_symlink Dir["#{frameworks}/Python.framework/Versions/#{xy}/lib/pkgconfig/*"]
+
+    # Remove the site-packages that Python created in its Cellar.
+    (prefix/"Frameworks/Python.framework/Versions/#{xy}/lib/python#{xy}/site-packages").rmtree
+
+    %w[setuptools pip wheel].each do |r|
+      (libexec/r).install resource(r)
+    end
+
+    # Remove wheel test data.
+    # It's for people editing wheel and contains binaries which fail `brew linkage`.
+    rm libexec/"wheel/tox.ini"
+    rm_r libexec/"wheel/tests"
+
+    # Install unversioned symlinks in libexec/bin.
+    {
+      "idle"          => "idle3",
+      "pydoc"         => "pydoc3",
+      "python"        => "python3",
+      "python-config" => "python3-config",
+    }.each do |unversioned_name, versioned_name|
+      (libexec/"bin").install_symlink (bin/versioned_name).realpath => unversioned_name
+    end
+  end
+
+  def post_install
+    ENV.delete "PYTHONPATH"
+
+    xy = (prefix/"Frameworks/Python.framework/Versions").children.min.basename.to_s
+    site_packages = HOMEBREW_PREFIX/"lib/python#{xy}/site-packages"
+    site_packages_cellar = prefix/"Frameworks/Python.framework/Versions/#{xy}/lib/python#{xy}/site-packages"
+
+    # Fix up the site-packages so that user-installed Python software survives
+    # minor updates, such as going from 3.3.2 to 3.3.3:
+
+    # Create a site-packages in HOMEBREW_PREFIX/lib/python#{xy}/site-packages
+    site_packages.mkpath
+
+    # Symlink the prefix site-packages into the cellar.
+    site_packages_cellar.unlink if site_packages_cellar.exist?
+    site_packages_cellar.parent.install_symlink site_packages
+
+    # Write our sitecustomize.py
+    rm_rf Dir["#{site_packages}/sitecustomize.py[co]"]
+    (site_packages/"sitecustomize.py").atomic_write(sitecustomize)
+
+    # Remove old setuptools installations that may still fly around and be
+    # listed in the easy_install.pth. This can break setuptools build with
+    # zipimport.ZipImportError: bad local file header
+    # setuptools-0.9.8-py3.3.egg
+    rm_rf Dir["#{site_packages}/setuptools*"]
+    rm_rf Dir["#{site_packages}/distribute*"]
+    rm_rf Dir["#{site_packages}/pip[-_.][0-9]*", "#{site_packages}/pip"]
+
+    %w[setuptools pip wheel].each do |pkg|
+      (libexec/pkg).cd do
+        system bin/"python3", "-s", "setup.py", "--no-user-cfg", "install",
+               "--force", "--verbose", "--install-scripts=#{bin}",
+               "--install-lib=#{site_packages}",
+               "--single-version-externally-managed",
+               "--record=installed.txt"
+      end
+    end
+
+    rm_rf [bin/"pip", bin/"easy_install"]
+    mv bin/"wheel", bin/"wheel3"
+
+    # Install unversioned symlinks in libexec/bin.
+    {
+      "easy_install" => "easy_install-#{xy}",
+      "pip"          => "pip3",
+      "wheel"        => "wheel3",
+    }.each do |unversioned_name, versioned_name|
+      (libexec/"bin").install_symlink (bin/versioned_name).realpath => unversioned_name
+    end
+
+    # post_install happens after link
+    %W[pip3 pip#{xy} easy_install-#{xy} wheel3].each do |e|
+      (HOMEBREW_PREFIX/"bin").install_symlink bin/e
+    end
+
+    # Help distutils find brewed stuff when building extensions
+    include_dirs = [HOMEBREW_PREFIX/"include", Formula["openssl@1.1"].opt_include,
+                    Formula["sqlite"].opt_include]
+    library_dirs = [HOMEBREW_PREFIX/"lib", Formula["openssl@1.1"].opt_lib,
+                    Formula["sqlite"].opt_lib]
+
+    cfg = prefix/"Frameworks/Python.framework/Versions/#{xy}/lib/python#{xy}/distutils/distutils.cfg"
+
+    cfg.atomic_write <<~EOS
+      [install]
+      prefix=#{HOMEBREW_PREFIX}
+      [build_ext]
+      include_dirs=#{include_dirs.join ":"}
+      library_dirs=#{library_dirs.join ":"}
+    EOS
+  end
+
+  def sitecustomize
+    xy = (prefix/"Frameworks/Python.framework/Versions").children.min.basename.to_s
+
+    <<~EOS
+      # This file is created by Homebrew and is executed on each python startup.
+      # Don't print from here, or else python command line scripts may fail!
+      # <https://docs.brew.sh/Homebrew-and-Python>
+      import re
+      import os
+      import sys
+      if sys.version_info[0] != 3:
+          # This can only happen if the user has set the PYTHONPATH for 3.x and run Python 2.x or vice versa.
+          # Every Python looks at the PYTHONPATH variable and we can't fix it here in sitecustomize.py,
+          # because the PYTHONPATH is evaluated after the sitecustomize.py. Many modules (e.g. PyQt4) are
+          # built only for a specific version of Python and will fail with cryptic error messages.
+          # In the end this means: Don't set the PYTHONPATH permanently if you use different Python versions.
+          exit('Your PYTHONPATH points to a site-packages dir for Python 3.x but you are running Python ' +
+               str(sys.version_info[0]) + '.x!\\n     PYTHONPATH is currently: "' + str(os.environ['PYTHONPATH']) + '"\\n' +
+               '     You should `unset PYTHONPATH` to fix this.')
+      # Only do this for a brewed python:
+      if os.path.realpath(sys.executable).startswith('#{rack}'):
+          # Shuffle /Library site-packages to the end of sys.path
+          library_site = '/Library/Python/#{xy}/site-packages'
+          library_packages = [p for p in sys.path if p.startswith(library_site)]
+          sys.path = [p for p in sys.path if not p.startswith(library_site)]
+          # .pth files have already been processed so don't use addsitedir
+          sys.path.extend(library_packages)
+          # the Cellar site-packages is a symlink to the HOMEBREW_PREFIX
+          # site_packages; prefer the shorter paths
+          long_prefix = re.compile(r'#{rack}/[0-9\._abrc]+/Frameworks/Python\.framework/Versions/#{xy}/lib/python#{xy}/site-packages')
+          sys.path = [long_prefix.sub('#{HOMEBREW_PREFIX/"lib/python#{xy}/site-packages"}', p) for p in sys.path]
+          # Set the sys.executable to use the opt_prefix, unless explicitly set
+          # with PYTHONEXECUTABLE:
+          if 'PYTHONEXECUTABLE' not in os.environ:
+              sys.executable = '#{opt_bin}/python#{xy}'
+    EOS
+  end
+
+  def caveats
+    xy = if prefix.exist?
+      (prefix/"Frameworks/Python.framework/Versions").children.min.basename.to_s
+    else
+      version.to_s.slice(/(3\.\d)/) || "3.9"
+    end
+    <<~EOS
+      Python has been installed as
+        #{HOMEBREW_PREFIX}/bin/python3
+
+      Unversioned symlinks `python`, `python-config`, `pip` etc. pointing to
+      `python3`, `python3-config`, `pip3` etc., respectively, have been installed into
+        #{opt_libexec}/bin
+
+      You can install Python packages with
+        pip3 install <package>
+      They will install into the site-package directory
+        #{HOMEBREW_PREFIX/"lib/python#{xy}/site-packages"}
+
+      See: https://docs.brew.sh/Homebrew-and-Python
+    EOS
+  end
+
+  test do
+    xy = (prefix/"Frameworks/Python.framework/Versions").children.min.basename.to_s
+    # Check if sqlite is ok, because we build with --enable-loadable-sqlite-extensions
+    # and it can occur that building sqlite silently fails if OSX's sqlite is used.
+    system "#{bin}/python#{xy}", "-c", "import sqlite3"
+    # Check if some other modules import. Then the linked libs are working.
+    system "#{bin}/python#{xy}", "-c", "import tkinter; root = tkinter.Tk()"
+    system "#{bin}/python#{xy}", "-c", "import _gdbm"
+    system "#{bin}/python#{xy}", "-c", "import zlib"
+    system bin/"pip3", "list", "--format=columns"
+  end
+end