import numpy as npimport pandas as pdfrom pandas import Series, DataFrameSeries reindexs1 = Series([1,2,3,4], index=['A','B','C','D'])s1A 1B 2C ...
NaN-means Not a Numberimport numpy as npimport pandas as pdfrom pandas import Series, DataFrame# 创建NaNn = np.nan# 类型type(n)float# 任何数字和nan做计算永远是nanm =...