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Alex Tirrell
3,359 Pointscount() is finding one too many correct answers
In order to find how many questions were answered correctly, I'm flattening my list of answer information and counting the number of True values in it. The flattened list is:
[35, True, datetime.timedelta(0, 3, 120616), 12, True, datetime.timedelta(0, 1, 348287), 6, False, datetime.timedelta(0, 1, 561616), 3, True, datetime.timedelta(0, 2, 859576), 3, True, datetime.timedelta(0, 1, 238063), 6, False, datetime.timedelta(0, 2, 471605), 4, True, datetime.timedelta(0, 2, 488742), 8, True, datetime.timedelta(0, 1, 910301), 80, True, datetime.timedelta(0, 1, 920059), 1, True, datetime.timedelta(0, 2, 17969)]
Counting the Trues in the list, you'll see there are eight. However, if I perform a .count(True) on the list, it returns 9. What's going on?
1 Answer
Steven Parker
231,236 Points
Your list includes the value 1, and 1 == True.
One way around this would be to get a count based on identity instead of equality using a comprehension:
truecount = len([1 for x in flatlist if x is True]))
Alex Tirrell
3,359 PointsAlex Tirrell
3,359 PointsOkay, I think I understand. I had thought about that as an issue, but I thought that python considered any integer above 0 as True, in which case there should have been a lot more false positives. Based on your answer, I'm assuming that "truthy" and "True" are not the same thing. I'm still not clear, though, in which cases any positive number will count as true, and in which cases it will only count "True" and "1". Can you help me out with that?