Fix syntax: "rc != None" -> "rc is not None"
diff --git a/Doc/library/subprocess.rst b/Doc/library/subprocess.rst
index 0dac62e..9f4b904 100644
--- a/Doc/library/subprocess.rst
+++ b/Doc/library/subprocess.rst
@@ -541,7 +541,7 @@
    pipe = os.popen("cmd", 'w')
    ...
    rc = pipe.close()
-   if rc != None and rc % 256:
+   if rc is not None and rc % 256:
        print "There were some errors"
    ==>
    process = Popen("cmd", 'w', shell=True, stdin=PIPE)