How should exceptions be handled if an "exception chain" occurs?

Question

Python

Please help/teach how to write exception handling code in Python 3.2.

Listing #9 here: Getting Started with Python 3: Part 2 More Advanced Topics has an example of an "exception chain".

I want to understand how to write exception handling code to prevent such chains?

I have the following situation:
1) In the self._executeTestCase() function I call the md5_of_file() function in the code of which open is called with the wrong input file name ".../pe.sdfasdf/???" which quite rightly flies IOError with Invalid parameter
2) The md5_of_file() call itself in the self._executeTestCase() code is framed in a try-except block, EnvironementError is caught in except, e.args[1] is written to the log and my type ExecuteTestCaseError is thrown
3) The self._executeTestCase() method is called in a loop inside the self._executeTestPlan() method and is framed in a try-except, with two exept branches. In the first one, ExecuteTestCaseError is caught, and in the second, BaseException Is

everything correct?

PS: Please do not kick the newbie, I'm still reading Lutz and these are the first steps in mastering the python)

Answer 1

The question is settled, due to inattention, I made a logging error in the except-block, and the logger object was received in the try-block.