Add note about `parse_command_line` function

diff --git a/tornado/options.py b/tornado/options.py
index 058f88d16d13eead342ce99be67bfcb105d40a81..993e673e70b4f19718a50f83321372a9421b5749 100644 (file)
--- a/tornado/options.py
+++ b/tornado/options.py
@@ -322,6 +322,10 @@ class OptionParser(object):
 
         Note that ``args[0]`` is ignored since it is the program name
         in `sys.argv`.
+        
+        Note that ``logging-related`` flags (such as ``log_to_stderr``,
+        ``log_file_prefix``) to options will not take effect if they
+        are setted after this line.
 
         We return a list of all arguments that are not parsed as options.