[Solved] Python: Is there any reason a subset of a list would sort differently than the original list?
[ad_1] I think I found why. That is because there are some nan in dpd.txt. And nan is unable to compare: float(‘nan’) > 1 # False while float(‘nan’) < 1 # False So this totally breaks comparison. If you change your key compare function to: def _key(id_): import math result = -dpd[index_map[id_]], id_.lower() if math.isnan(result[0]): … Read more