Simplify `easy_install.update_pth`

setuptools/command/easy_install.py

@@ -1196,11 +1196,13 @@ class easy_install(Command):
             return
 
         for d in self.pth_file[dist.key]:  # drop old entries
-            if self.multi_version or d.location != dist.location:
-                log.info("Removing %s from easy-install.pth file", d)
-                self.pth_file.remove(d)
-                if d.location in self.shadow_path:
-                    self.shadow_path.remove(d.location)
+            if not self.multi_version and d.location == dist.location:
+                continue
+
+            log.info("Removing %s from easy-install.pth file", d)
+            self.pth_file.remove(d)
+            if d.location in self.shadow_path:
+                self.shadow_path.remove(d.location)
 
         if not self.multi_version:
             if dist.location in self.pth_file.paths:
@@ -1214,19 +1216,21 @@ class easy_install(Command):
                 if dist.location not in self.shadow_path:
                     self.shadow_path.append(dist.location)
 
-        if not self.dry_run:
+        if self.dry_run:
+            return
 
-            self.pth_file.save()
+        self.pth_file.save()
 
-            if dist.key == 'setuptools':
-                # Ensure that setuptools itself never becomes unavailable!
-                # XXX should this check for latest version?
-                filename = os.path.join(self.install_dir, 'setuptools.pth')
-                if os.path.islink(filename):
-                    os.unlink(filename)
-                f = open(filename, 'wt')
-                f.write(self.pth_file.make_relative(dist.location) + '\n')
-                f.close()
+        if dist.key != 'setuptools':
+            return
+
+        # Ensure that setuptools itself never becomes unavailable!
+        # XXX should this check for latest version?
+        filename = os.path.join(self.install_dir, 'setuptools.pth')
+        if os.path.islink(filename):
+            os.unlink(filename)
+        with open(filename, 'wt') as f:
+            f.write(self.pth_file.make_relative(dist.location) + '\n')
 
     def unpack_progress(self, src, dst):
         # Progress filter for unpacking