Rename requirements named *Dependency.

Dependency is another similar, related class and it's super confusing
to have some Requirements that are named *Dependency.

Closes Homebrew/homebrew#38891.

Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>

1 files changed, 58 insertions, 0 deletions

diff --git a/Library/Homebrew/requirements/python_requirement.rb b/Library/Homebrew/requirements/python_requirement.rb
new file mode 100644
index 000000000..df9d7328c
--- /dev/null
+++ b/Library/Homebrew/requirements/python_requirement.rb
@@ -0,0 +1,58 @@
+require "language/python"
+
+class PythonRequirement < Requirement
+  fatal true
+  default_formula "python"
+  cask "python"
+
+  satisfy :build_env => false do
+    python = which_python
+    next unless python
+    version = python_short_version
+    next unless version
+    # Always use Python 2.7 for consistency on older versions of OSX.
+    version == Version.new("2.7")
+  end
+
+  def pour_bottle?
+    build? || system_python?
+  end
+
+  env do
+    if system_python?
+      if python_binary == "python"
+        version = python_short_version
+        ENV["PYTHONPATH"] = "#{HOMEBREW_PREFIX}/lib/python#{version}/site-packages"
+      end
+    elsif which_python
+      ENV.prepend_path "PATH", which_python.dirname
+    end
+  end
+
+  def python_short_version
+    @short_version ||= Language::Python.major_minor_version which_python
+  end
+
+  def which_python
+    python = which python_binary
+    return unless python
+    Pathname.new Utils.popen_read(python, "-c", "import sys; print(sys.executable)").strip
+  end
+
+  def system_python; "/usr/bin/#{python_binary}" end
+  def system_python?; system_python == which_python.to_s end
+  def python_binary; "python" end
+
+  # Deprecated
+  alias_method :to_s, :python_binary
+end
+
+class Python3Requirement < PythonRequirement
+  fatal true
+  default_formula "python3"
+  cask "python3"
+
+  satisfy(:build_env => false) { which_python }
+
+  def python_binary; "python3" end
+end