python_requirement: fix ENV for python3

Closes Homebrew/homebrew#43453.

1 files changed, 5 insertions, 3 deletions

diff --git a/Library/Homebrew/requirements/python_requirement.rb b/Library/Homebrew/requirements/python_requirement.rb
index f41722782..d4e4a116d 100644
--- a/Library/Homebrew/requirements/python_requirement.rb
+++ b/Library/Homebrew/requirements/python_requirement.rb
@@ -24,9 +24,7 @@ class PythonRequirement < Requirement
       ENV.prepend_path "PATH", Formula["python"].opt_bin
     end
 
-    if python_binary == "python"
-      ENV["PYTHONPATH"] = "#{HOMEBREW_PREFIX}/lib/python#{short_version}/site-packages"
-    end
+    ENV["PYTHONPATH"] = "#{HOMEBREW_PREFIX}/lib/python#{short_version}/site-packages"
   end
 
   def python_short_version
@@ -62,6 +60,10 @@ class Python3Requirement < PythonRequirement
 
   satisfy(:build_env => false) { which_python }
 
+  env do
+    ENV["PYTHONPATH"] = "#{HOMEBREW_PREFIX}/lib/python#{python_short_version}/site-packages"
+  end
+
   def python_binary
     "python3"
   end