Python 2.x and 3.x support

New `depends_on :python` Dependency.
New `depends_on :python3` Dependency.

To avoid having multiple formulae with endings -py2 and -py3,
we will handle support for different pythons (2.x vs. 3.x)
in the same formula.
Further brewed vs. external python will be transparently supported.

The formula also gets a new object `python`, which is false if
no Python is available or the user has disabled it. Otherwise
it is defined and provides several support methods:

python.site_packages # the site-packages in the formula's Cellar
python.global_site_packages
python.binary # the full path to the python binary
python.prefix
python.version
python.version.major
python.version.minor
python.xy # => e.g. "python2.7"
python.incdir # includes of python
python.libdir # the python dylib library
python.pkg_config_path # used internally by brew
python.from_osx?
python.framework?
python.universal?
python.pypy?
python.standard_caveats # Text to set PYTHONPATH for python.from_osx?
python.if3then3 # => "" for 2.x and to "3" for 3.x.

Further, to avoid code duplication, `python` takes an optional
block that is run twice if the formula defines depends_on
:python AND :python3.

python do
  system python, 'setup.py', "--prefix=#{prefix}"
end

Read more in the Homebrew wiki.

1 files changed, 12 insertions, 12 deletions

diff --git a/Library/Formula/bulk_extractor.rb b/Library/Formula/bulk_extractor.rb
index 7991f1d90..64a031729 100644
--- a/Library/Formula/bulk_extractor.rb
+++ b/Library/Formula/bulk_extractor.rb
@@ -7,6 +7,7 @@ class BulkExtractor < Formula
 
   depends_on :autoconf
   depends_on :automake
+  depends_on :python
 
   depends_on 'afflib' => :optional
   depends_on 'exiv2' => :optional
@@ -19,25 +20,24 @@ class BulkExtractor < Formula
   end
 
   def install
-    system "./configure", "--disable-dependency-tracking",
-                          "--prefix=#{prefix}"
-    system "make"
-    system "make install"
+    python do
+      system "./configure", "--disable-dependency-tracking",
+                            "--prefix=#{prefix}"
+      system "make"
+      system "make install"
 
-    # Install documentation
-    (share/'bulk_extractor/doc').install Dir['doc/*.{html,txt,pdf}']
+      # Install documentation
+      (share/'bulk_extractor/doc').install Dir['doc/*.{html,txt,pdf}']
 
-    # Install Python utilities
-    (share/'bulk_extractor/python').install Dir['python/*.py']
+      (lib/python.xy/"site-packages").install Dir['python/*.py']
+    end
 
     # Install the GUI the Homebrew way
     libexec.install 'java_gui/BEViewer.jar'
     bin.write_jar_script libexec/"BEViewer.jar", "BEViewer", "-Xmx1g"
   end
 
-  def caveats; <<-EOS.undent
-    You may need to add the directory containing the Python bindings to your PYTHONPATH:
-      #{share}/bulk_extractor/python
-    EOS
+  def caveats
+    python.standard_caveats if python
   end
 end