python pandas v.12 v.13 相同的代码日期时间

Question

我的代码在使用 pandas V.12 的计算机上运行，​​但不能在使用 V.13 的计算机上运行。是 v.13 jenkins-pandas-windows-test-py27-1193 吗？使用此代码

import pandas as pd
from datetime import datetime
d = {   'File' : pd.Series([2., 2.]), 
    'Status' : pd.Series([1., 1.]), 
    'Error' : pd.Series([2., 2.]), 
    'AlertDays' : pd.Series([2., 2.]), 
    'Date' : pd.Series([datetime(2012, 5, 2), datetime(2012, 5, 2)])}
df=pd.DataFrame(d)
df['Date']=pd.to_datetime(df['Date'])
xx=df.groupby('File')['Date'].max()
xx=pd.DataFrame(xx).reset_index()
df=pd.merge(xx,df,on=['File','Date'],how='left')
df['diff'] = df.apply(lambda x: (datetime.now() - x['Date']).days, axis=1)

我得到这个输出

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "C:\Python27\lib\site-packages\pandas\core\frame.py", line 3431, in apply

    return self._apply_standard(f, axis, reduce=reduce)
  File "C:\Python27\lib\site-packages\pandas\core\frame.py", line 3501, in _appl
y_standard
    results[i] = func(v)
  File "<stdin>", line 1, in <lambda>
TypeError: ("unsupported operand type(s) for -: 'datetime.datetime' and 'float'"
, u'occurred at index 0')

Answer 1

一个错误...这样做(而不是最大)

In [23]: df.groupby('File')['Date'].apply(lambda x: x.max())
Out[23]: 
File
2      2012-05-02 00:00:00
dtype: datetime64[ns]