in the thinkstats.py module, the Trim function creates a (documented) side effect of sorting the sequence that is passed in as a parameter. Instead of using the sort() method on the list, use the sorted builtin to sort the values into another array.

Existing code --

def Trim(t, p=0.01): t.sort() n = int(p * len(t)) t = t[n:-n] return t

Proposed code --

def Trim(t, p=0.01): sorted_t = sorted(t) n = int(p * len(sorted_t)) return sorted_t[n:-n]

Of course, the comments and documentation would have to be updated as well.

Done. Thanks for the suggestion.