python笔记：4.1.1.1统计量

# -*- coding: utf-8 -*- """ Created on Sat May 25 23:11:30 2019 @author: User """ import pandas as pd import numpy as np stock=np.dtype([('id',np.str,5), ('time',np.str,10), ('code',np.str,10), ('open_p',np.float64), ('close_p',np.float64), ('low_p',np.float64), ('vol',np.int32), ('high_p',np.float64), ('col',np.int32)]) print('\n np.loadtxt:') jd_stock=np.loadtxt('data\stock.csv',delimiter=',',dtype=stock) print(jd_stock) print('\n pd.read_table:') jddf=pd.read_csv('data\stock.csv',sep=',',header=None, names=['id','time','code','open_p','colse_p','low_p','vol','high_p','col']) print(jddf.head()) print("\n np.mean(jd_stock['open_p']):") print(np.mean(jd_stock['open_p'])) print("\n np.average(jd_stock['open_p']):") print(np.average(jd_stock['open_p'])) print("\n np.average加权平均 np.average(jd_stock['open_p'], weights=jd_stock['vol']):") print(np.average(jd_stock['open_p'], weights=jd_stock['vol']))

运行：

 np.loadtxt: [('1', '20130902', '600028', 4.41, 4.43, 4.37,  17275, 4.41,  392662)  ('2', '20130903', '600028', 4.41, 4.46, 4.4 ,  19241, 4.45,  434177)  ('3', '20130904', '600028', 4.44, 4.49, 4.42,  20106, 4.47,  451470) ...  ('1356', '20190327', '600028', 5.71, 5.75, 5.69,  63601, 5.72, 1112544)  ('1357', '20190328', '600028', 5.69, 5.7 , 5.62,  65692, 5.64, 1162484)  ('1358', '20190329', '600028', 5.65, 5.75, 5.61, 112785, 5.74, 1981482)]

 pd.read_table:    id      time    code  open_p  colse_p  low_p       vol  high_p     col 0   1  20130902  600028    4.41     4.43   4.37  17275.39    4.41  392662 1   2  20130903  600028    4.41     4.46   4.40  19241.84    4.45  434177 2   3  20130904  600028    4.44     4.49   4.42  20106.30    4.47  451470 3   4  20130905  600028    4.47     4.48   4.42  15582.48    4.47  349997 4   5  20130906  600028    4.46     4.52   4.45  19101.41    4.50  425777

 np.mean(jd_stock['open_p']): 5.658718703976436

 np.average(jd_stock['open_p']): 5.658718703976436

 np.average加权平均 np.average(jd_stock['open_p'], weights=jd_stock['vol']): 6.362912722690805