W3School TIY Editor

# 导入数学库 import math # 检查某些值是否为非数字 (NaN) print(math.isnan(56)) print(math.isnan(-45.34)) print(math.isnan(+45.34)) print(math.isnan(math.inf)) print(math.isnan(float("nan"))) print(math.isnan(float("inf"))) print(math.isnan(float("-inf"))) print(math.isnan(math.nan))