Dear Developers, I am a Ph.D student from Case Western Reserve University, specialized at software engineering. Our recent approach analyzes bugs that are being fixed in the issue database, and tries to discover any latent bug instances that are the same as the fixed bug but are left unfixed. We have found some spurious code in your project in this approach, and pointed out these code by comments (sometimes also with patches) to the fixed bugs in the issue DB from which it is discovered as follows: Issue 6817: http://bugs.python.org/issue6817 (A new issue, created following Amaury's comments) Issue 2620: http://bugs.python.org/issue2620 Issue 3139: http://bugs.python.org/issue3139 Issue 5705: http://bugs.python.org/issue5705 We hope that we have discovered some real bugs for you. Any comments or suggestions are GREATLY appreciated, since your opinions are very, very precious to us. Boya -- BOYA SUN Computer Science Division Electrical Engineering & Computer Science Department 513 Olin Building Case Western Reserve University 10900 Euclid Avenue Cleveland, OH 44106 boya.sun@case.edu