Hi there,
I have an experience of programming with python for over 5 years and this task of flattening an xml is a pretty simple one. I am pretty new to freelancer and hence might not have a lot of reviews as compared to the other bidders, but you can surely take a look at the reviews that I have to see the quality of the work that I provide.
This is a simple task and my only query would be to know what exactly do you want in the flattened xml file, all the data arranged in what exact order, etc.
I will complete this in a day's time and the work will be to your satisfaction. I will provide unlimited revisions until you are satisfied with the job. I am your guy for this job :D
Looking forward to working with you