I have found a lot of material on removing duplicates from a list, but I
am trying to find the most efficient way to just check for the existence
of duplicates in a list. Here is the best I have come up with so far:
CheckList = [x[ValIndex] for x in self.__XRList[z]]
FilteredList = filter((lambda x:x != 0),CheckList)
if len(FilteredList) > len(sets.Set(FilteredList)): return
False
The first statement pulls the slice out of a matrix I need to check.
The filter statement gets rid of zeroes (they don't count as duplicates).
The if statement is the actual duplicates check
This is in a program that generates random numbers to do a brute force
solve on a sudoku-like puzzle. Once a certain level of difficulty in
the puzzle is reached, performance goes off a cliff because the
duplicate checking code, although fast, is executed so many times.
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