setup.py: minor non-functional changes

setup.py

@@ -11,12 +11,12 @@ ev_dir = None
 
 if ev_dir is None and ( glob.glob('/usr/lib/libevent*') or glob.glob('/usr/lib64/libevent*') ):
     print 'found system libevent for', sys.platform
-    libevent = Extension(name=name,
+    gevent_core = Extension(name=name,
                             sources=sources,
                             libraries=['event'])
 elif ev_dir is None and glob.glob('%s/lib/libevent.*' % sys.prefix):
     print 'found installed libevent in', sys.prefix
-    libevent = Extension(name=name,
+    gevent_core = Extension(name=name,
                             sources=sources,
                             include_dirs=['%s/include' % sys.prefix],
                             library_dirs=['%s/lib' % sys.prefix],
@@ -25,9 +25,9 @@ else:
     if ev_dir is None:
         l = glob.glob('../libevent*')
         l.reverse()
-        for dir in l:
-            if os.path.isdir(dir):
-                ev_dir = dir
+        for path in l:
+            if os.path.isdir(path):
+                ev_dir = path
                 break
     if ev_dir:
         print 'found libevent build directory', ev_dir
@@ -47,7 +47,7 @@ else:
         else:
             ev_extobjs = glob.glob('%s/*.o' % dir)
 
-        libevent = Extension(name=name,
+        gevent_core = Extension(name=name,
                                 sources=sources,
                                 include_dirs=ev_incdirs,
                                 extra_compile_args=ev_extargs,
@@ -55,21 +55,22 @@ else:
                                 libraries=ev_libraries)
     else:
         sys.stderr.write("\nWARNING: couldn't find libevent installation or build directory: assuming system-wide libevent is installed.\n\n")
-        libevent = Extension(name=name,
+        gevent_core = Extension(name=name,
                                 sources=sources,
                                 libraries=['event'])
 
 version = re.search("__version__\s*=\s*'(.*)'", open('gevent/__init__.py').read(), re.M).group(1).strip()
 assert version, version
 
-setup(
+if __name__ == '__main__':
+    setup(
         name='gevent',
         version=version,
         description='Python network library that uses greenlet and libevent for easy and scalable concurrency',
         author='Denis Bilenko',
         author_email='denis.bilenko@gmail.com',
         packages=['gevent'],
-    ext_modules=[libevent],
+        ext_modules=[gevent_core],
         classifiers=[
         "License :: OSI Approved :: MIT License",
         "Programming Language :: Python",