关于Python数据分析基础教程 Numpy学习指南 第二版 第三章中代码所呈现的问题

关于第三章 3.13日期分析

>>> def datestr2num(s):

return datetime.datetime.strptime

(s,"%d-%m-%Y").date().weekday()

报出这样的错误

Traceback (most recent call last):

File "<pyshell#59>", line 1, in <module>

dates, close=np.loadtxt('H:\pythonsta\Code\ch3code\data.csv', delimiter=',', usecols=(1,6), converters={1: datestr2num}, unpack=True)

File "D:\Program Files\Python27\lib\site-packages\numpy\lib\npyio.py", line 860, in loadtxt

items = [conv(val) for (conv, val) in zip(converters, vals)]

File "<pyshell#56>", line 2, in datestr2num

return datetime.datetime.strptime

AttributeError: type object 'datetime.datetime' has no attribute 'datetime'

应该把上述的代码改为：

>>> def datestr2num(s):

return datetime.strptime(s, "%d-%m-%Y").date().weekday()