Extract a method to capture the intention of caller detection.

setuptools/command/install.py

@@ -52,19 +52,8 @@ class install(_install):
         if self.old_and_unmanageable or self.single_version_externally_managed:
             return _install.run(self)
 
-        # Attempt to detect whether we were called from setup() or by another
-        # command.  If we were called by setup(), our caller will be the
-        # 'run_command' method in 'distutils.dist', and *its* caller will be
-        # the 'run_commands' method.  If we were called any other way, our
-        # immediate caller *might* be 'run_command', but it won't have been
-        # called by 'run_commands'.  This is slightly kludgy, but seems to
-        # work.
-        #
-        caller = sys._getframe(2)
-        caller_module = caller.f_globals.get('__name__','')
-        caller_name = caller.f_code.co_name
-
-        if caller_module != 'distutils.dist' or caller_name!='run_commands':
+        called_from_setup = self._called_from_setup(sys._getframe(2))
+        if not called_from_setup:
             # We weren't called from the command line or setup(), so we
             # should run in backward-compatibility mode to support bdist_*
             # commands.
@@ -72,6 +61,25 @@ class install(_install):
         else:
             self.do_egg_install()
 
+    @staticmethod
+    def _called_from_setup(run_parent_parent):
+        """
+        Attempt to detect whether we were called from setup() or by another
+        command.  If we were called by setup(), our caller will be the
+        'run_command' method in 'distutils.dist', and *its* caller will be
+        the 'run_commands' method.  If we were called any other way, our
+        immediate caller *might* be 'run_command', but it won't have been
+        called by 'run_commands'.  This is slightly kludgy, but seems to
+        work.
+        """
+        caller = run_parent_parent
+        caller_module = caller.f_globals.get('__name__','')
+        caller_name = caller.f_code.co_name
+        return (
+            caller_module == 'distutils.dist'
+            and caller_name == 'run_commands'
+        )
+
     def do_egg_install(self):
 
         easy_install = self.distribution.get_command_class('easy_install')