=None, dropna=True)
作用:返回一个包含值和该值出现次数的Series对象,次序按照出现的频率由高到低排序....返回指定轴上值的和....(data=[[1.4,np.nan],[7.1,-4.5],[np.nan,np.nan],[0.75,-1.3]], index=["a","b","c","d"],...2、pandas.dataframe.mean
返回指定轴上值的平均数....例子:
import numpy as np
import pandas as pd
df=pd.DataFrame(data=[[1.4,np.nan],[7.1,-4.5],[np.nan,np.nan