python: better site-packages and install-scripts

Previous versions of the Python 2.x formula did not set up the
site-packages and install-scripts folders in a way friendly to updates
of Python itself.

3 files changed, 75 insertions, 245 deletions

diff --git a/Library/Formula/distribute.rb b/Library/Formula/distribute.rb
deleted file mode 100644
index 181cb894a..000000000
--- a/Library/Formula/distribute.rb
+++ /dev/null
@@ -1,45 +0,0 @@
-require 'formula'
-
-class Distribute < Formula
-  url 'http://pypi.python.org/packages/source/d/distribute/distribute-0.6.14.tar.gz'
-  homepage 'http://pypi.python.org/pypi/distribute/0.6.14'
-  md5 'ac607e05682116c06383b27a15e2db90'
-
-  def caveats
-    <<-EOS.undent
-      This formula is only meant to be used against a Homebrew-built Python.
-      It will install itself directly into Python's location in the Cellar.
-    EOS
-  end
-
-  def install
-    python = Formula.factory("python")
-    unless python.installed?
-      onoe "The Distribute brew is only meant to be used against a Homebrew-built Python."
-      puts <<-EOS
-        Homebrew's "distribute" formula is only meant to be installed against a Homebrew-
-        built version of Python, but we couldn't find such a version.
-
-        The system-provided Python comes with "easy_install" already installed, with the
-        caveat that some Python packages don't install cleanly against Apple's customized
-        versions of Python.
-
-        To install distribute against a custom Python, download distribute from:
-          http://pypi.python.org/pypi/distribute
-        unzip, and run:
-          /path/to/custom/python setup.py install
-      EOS
-      exit 99
-    end
-
-    system "#{python.bin}/python", "setup.py", "install",
-              "--install-scripts", bin,
-              "--install-purelib", python.site_packages,
-              "--install-platlib", python.site_packages
-
-    (prefix+"README.homebrew").write <<-EOF
-distribute's libraries were installed directly into:
-  #{python.site_packages}
-EOF
-  end
-end
diff --git a/Library/Formula/pip.rb b/Library/Formula/pip.rb
deleted file mode 100644
index 3295ea8a9..000000000
--- a/Library/Formula/pip.rb
+++ /dev/null
@@ -1,108 +0,0 @@
-require 'formula'
-
-class Pip < Formula
-  url 'http://pypi.python.org/packages/source/p/pip/pip-0.8.2.tar.gz'
-  homepage 'http://pip.openplans.org/'
-  md5 'df1eca0abe7643d92b5222240bed15f6'
-
-  depends_on 'distribute'
-
-  def patches
-    # Create a locations branch for darwin with placeholders
-    DATA
-  end
-
-  def install
-    python = Formula.factory("python")
-    unless python.installed?
-      onoe "The \"pip\" brew is only meant to be used against a Homebrew-built Python."
-      puts <<-EOS
-        Homebrew's "pip" formula is only meant to be installed against a Homebrew-
-        built version of Python, but we couldn't find such a version.
-
-        The system-provided Python comes with "easy_install" already installed, with the
-        caveat that some Python packages don't install cleanly against Apple's customized
-        versions of Python.
-
-        To install pip against a custom Python:
-        First download distribute from:
-          http://pypi.python.org/pypi/distribute
-        unzip, and run:
-          /path/to/custom/python setup.py install
-
-        Then download pip from:
-          http://pypi.python.org/pypi/pip
-        unzip, and run:
-          /path/to/custom/python setup.py install
-      EOS
-      exit 99
-    end
-
-    inreplace 'pip/locations.py' do |s|
-      # Replace placeholders with HOMEBREW paths
-      s.gsub! '#BUILD_PREFIX#', "'#{var}/pip/build'"
-      s.gsub! '#SRC_PREFIX#', "'#{var}/pip/src'"
-      s.gsub! '#STORAGE_DIR#', "'#{var}/pip'"
-      s.gsub! '#CONFIG_FILE#', "'#{etc}/pip.conf'"
-      s.gsub! '#LOG_FILE#', "'#{var}/pip/pip.log'"
-    end
-
-    system "#{python.bin}/python", "setup.py", "install",
-              "--install-scripts", bin,
-              "--install-purelib", python.site_packages,
-              "--install-platlib", python.site_packages
-
-    (prefix+"README.homebrew").write <<-EOF
-pip's libraries were installed directly into:
-  #{python.site_packages}
-EOF
-  end
-
-  def caveats
-    <<-EOS.undent
-      This formula is only meant to be used against a Homebrew-built Python.
-      It will install itself directly into Python's location in the Cellar.
-
-      Pip's configuration file lives at:
-        #{etc}/pip.conf
-    EOS
-  end
-end
-
-
-__END__
-diff --git a/pip/locations.py b/pip/locations.py
-index 4254ef2..0a31cc2 100644
---- a/pip/locations.py
-+++ b/pip/locations.py
-@@ -19,8 +19,8 @@ if running_under_virtualenv():
-     src_prefix = os.path.join(sys.prefix, 'src')
- else:
-     ## FIXME: this isn't a very good default
--    build_prefix = os.path.join(os.getcwd(), 'build')
--    src_prefix = os.path.join(os.getcwd(), 'src')
-+    build_prefix = #BUILD_PREFIX#
-+    src_prefix = #SRC_PREFIX#
- 
- # FIXME doesn't account for venv linked to global site-packages
- 
-@@ -35,11 +35,16 @@ if sys.platform == 'win32':
-     default_storage_dir = os.path.join(user_dir, 'pip')
-     default_config_file = os.path.join(default_storage_dir, 'pip.ini')
-     default_log_file = os.path.join(default_storage_dir, 'pip.log')
-+elif sys.platform[:6] == 'darwin':
-+    bin_py = os.path.join(sys.prefix, 'bin')
-+    default_storage_dir = #STORAGE_DIR#
-+    default_config_file = #CONFIG_FILE#
-+    default_log_file = #LOG_FILE#
-+    # Forcing to use /usr/local/bin for standard Mac OS X framework installs
-+    if sys.prefix[:16] == '/System/Library/':
-+        bin_py = '/usr/local/bin'
- else:
-     bin_py = os.path.join(sys.prefix, 'bin')
-     default_storage_dir = os.path.join(user_dir, '.pip')
-     default_config_file = os.path.join(default_storage_dir, 'pip.conf')
-     default_log_file = os.path.join(default_storage_dir, 'pip.log')
--    # Forcing to use /usr/local/bin for standard Mac OS X framework installs
--    if sys.platform[:6] == 'darwin' and sys.prefix[:16] == '/System/Library/':
--        bin_py = '/usr/local/bin'
diff --git a/Library/Formula/python.rb b/Library/Formula/python.rb
index d7d22790c..d5c6264e9 100644
--- a/Library/Formula/python.rb
+++ b/Library/Formula/python.rb
@@ -1,43 +1,13 @@
 require 'formula'
 
-<<-COMMENTS
-Versions
---------
-This formula is currently tracking version 2.7.x.
+# This formula for Python 2.7.1
+# Python 3.x is available as a separate formula:
+# $ brew install python3
 
-Python 3.x is available as a separate formula:
-  brew install python3
-
-Options
--------
-There are a few options for customzing the build.
-  --universal: Builds combined 32-/64-bit Intel binaries.
-  --framework: Builds a "Framework" version of Python.
-  --static:    Builds static instead of shared libraries.
-  --no-poll:   Don't include Apple's broken poll implementation.
-
-site-packages
--------------
-The "site-packages" folder lives in the Cellar, under the "lib" folder
-for normal builds, and under the "Frameworks" folder for Framework builds.
-
-A .pth file is added to the Cellar site-packages that adds the corresponding
-HOMEBREW_PREFIX folder (/usr/local/lib/python2.7/site-packages by default)
-to sys.path. Note that this alternate folder doesn't itself support .pth files.
-
-pip / distribute
-----------------
-The pip (and distribute) formulae in Homebrew are designed only to work
-against a Homebrew-installed Python, though they provide links for
-manually installing against a custom Python.
-
-pip and distribute are installed directly into the Cellar site-packages,
-since they need to install to a place that supports .pth files.
-
-The pip & distribute formuale use the "site_packages" method defined here
-to get the appropriate site-packages path.
-
-COMMENTS
+class Distribute < Formula
+  url 'http://pypi.python.org/packages/source/d/distribute/distribute-0.6.15.tar.gz'
+  md5 'ea52e1412e7ff560c290266ed400e216'
+end
 
 
 # Was a Framework build requested?
@@ -53,8 +23,8 @@ class Python < Formula
   homepage 'http://www.python.org/'
   md5 'aa27bc25725137ba155910bd8e5ddc4f'
 
-  depends_on 'readline' => :optional  # Prefer over OS X's libedit
-  depends_on 'sqlite'   => :optional  # Prefer over OS X's older version
+  depends_on 'readline' => :optional # Prefer over OS X's libedit
+  depends_on 'sqlite'   => :optional # Prefer over OS X's older version
   depends_on 'gdbm'     => :optional
 
   def options
@@ -69,41 +39,11 @@ class Python < Formula
   # Skip binaries so modules will load; skip lib because it is mostly Python files
   skip_clean ['bin', 'lib']
 
-  def site_packages
-    # The Cellar location of site-packages
-    if as_framework?
-      # If we're installed or installing as a Framework, then use that location.
-      return prefix+"Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages"
-    else
-      # Otherwise use just 'lib'
-      return lib+"python2.7/site-packages"
-    end
-  end
-
-  def exec_prefix
-    if as_framework?
-      # If we're installed or installing as a Framework, then use that location.
-      return prefix+"Frameworks/Python.framework/Versions/2.7/bin"
-    else
-      # Otherwise just use 'bin'
-      return bin
-    end
-  end
-
-  def prefix_site_packages
-    # The HOMEBREW_PREFIX location of site-packages
-    HOMEBREW_PREFIX+"lib/python2.7/site-packages"
-  end
-
-  def validate_options
+  def install
     if build_framework? and ARGV.include? "--static"
       onoe "Cannot specify both framework and static."
       exit 99
     end
-  end
-
-  def install
-    validate_options
 
     args = ["--prefix=#{prefix}"]
 
@@ -119,8 +59,7 @@ class Python < Formula
 
     # allow sqlite3 module to load extensions
     inreplace "setup.py",
-      'sqlite_defines.append(("SQLITE_OMIT_LOAD_EXTENSION", "1"))',
-      '#sqlite_defines.append(("SQLITE_OMIT_LOAD_EXTENSION", "1"))'
+      'sqlite_defines.append(("SQLITE_OMIT_LOAD_EXTENSION", "1"))', ''
 
     system "./configure", *args
 
@@ -132,13 +71,36 @@ class Python < Formula
     ENV.j1 # Installs must be serialized
     system "make install"
 
-    # Add the Homebrew prefix path to site-packages via a .pth
+    # Post-install, fix up the site-packages and install-scripts folders
+    # so that user-installed Python software survives minor updates, such
+    # as going from 2.7.0 to 2.7.1.
+
+    # Remove the site-packages that Python created in its Cellar.
+    site_packages.rmtree
+
+    # Create a site-packages in the prefix.
     prefix_site_packages.mkpath
-    (site_packages+"homebrew.pth").write prefix_site_packages
+
+    # Symlink the prefix site-packages into the cellar.
+    ln_s prefix_site_packages, site_packages
+
+    # Tell distutils-based installers where to put scripts
+    scripts_folder.mkpath
+    (effective_lib+"python2.7/distutils/distutils.cfg").write <<-EOF.undent
+      [install]
+      install-scripts=#{scripts_folder}
+    EOF
+
+    # Install distribute. The user can then do:
+    # $ easy_install pip
+    # $ pip install --upgrade distribute
+    # to get newer versions of distribute outside of Homebrew.
+    Distribute.new.brew { system "#{bin}/python", "setup.py", "install" }
   end
 
   def caveats
     framework_caveats = <<-EOS.undent
+
       Framework Python was installed to:
         #{prefix}/Frameworks/Python.framework
 
@@ -146,31 +108,52 @@ class Python < Formula
       such as:
         mkdir ~/Frameworks
         ln -s "#{prefix}/Frameworks/Python.framework" ~/Frameworks
-
     EOS
 
-    site_caveats = <<-EOS.undent
-      The site-packages folder for this Python is:
-        #{site_packages}
+    general_caveats = <<-EOS.undent
+      A "distutils.cfg" has been written, specifing the install-scripts folder as:
+        #{scripts_folder}
 
-      We've added a "homebrew.pth" file to also include:
-        #{prefix_site_packages}
+      If you install Python packages via "python setup.py install", easy_install, pip,
+      any provided scripts will go into the install-scripts folder above, so you may
+      want to add it to your PATH.
 
-    EOS
+      Distribute has been installed, so easy_install is available.
+      To update distribute itself outside of Homebrew:
+      $ easy_install pip
+      $ pip install --upgrade distribute
 
-    general_caveats = <<-EOS.undent
-      You may want to create a "virtual environment" using this Python as a base
-      so you can manage multiple independent site-packages. See:
-        http://pypi.python.org/pypi/virtualenv
-
-      If you install Python packages via pip, binaries will be installed under
-      Python's cellar but not automatically linked into the Homebrew prefix.
-      You may want to add Python's bin folder to your PATH as well:
-        #{exec_prefix}
+      See: https://github.com/mxcl/homebrew/wiki/Homebrew-and-Python
     EOS
 
-    s = site_caveats+general_caveats
-    s = framework_caveats + s if as_framework?
+    s = general_caveats
+    s += framework_caveats if as_framework?
     return s
   end
+
+private
+
+  # Path helpers
+
+  def effective_lib
+    # If we're installed or installing as a Framework, then use that location.
+    return prefix+"Frameworks/Python.framework/Versions/2.7/lib" if as_framework?
+    # Otherwise use just 'lib'
+    return lib
+  end
+
+  # The Cellar location of site-packages
+  def site_packages
+    effective_lib + "python2.7/site-packages"
+  end
+
+  # The HOMEBREW_PREFIX location of site-packages
+  def prefix_site_packages
+    HOMEBREW_PREFIX+"lib/python2.7/site-packages"
+  end
+
+  def scripts_folder
+    HOMEBREW_PREFIX+"share/python"
+  end
+
 end