I was having some fun writing SRM 586's editorial. Since I am now allowed to use python code I was giving it a try. Could make some very short looking stuff. However, I eventually noticed that my code for div2 250 was not actually working in TopCoder's servers - Giving a runtime error about tuples not having the remove attribute. They were working fine locally. My first reaction was to assume that TopCoder's python version was old. So I tried to instal python 2.6 instead of my local 2.7... Still the same error.
Eventually I figured, ffao's python implementation was making KawigiEdit generate "array" function arguments as lists [a,b,c,d] . But TopCoder's server sends them as tuples (a,b,c,d). So I had to make a new release for KawigiEdit-pf.
Of course, in reality I first updated my KawigiEdit mod. The KawigiEdit-pfx version in that post has been updated too.