熊貓更新週末日期最近的業務

Question

天

我有一個目前看起來是這樣的一個數據幀：

raw_data = {'AllDate':['2017-04-05','2017-04-06','2017-04-07','2017-04-08','2017-04-09']} 
import pandas as pd 
df = pd.DataFrame(raw_data,columns=['AllDate']) 
print df 

我想一個WeekDate列到這個數據幀添加比如如果在「AllDate」的date在週末，「WeekDate」專欄的日期從週五開始。如果日期屬於工作日，日期應該保持不變。

舉例來說，所產生的數據幀應該是這樣的：

raw_data = {'AllDate':['2017-04-05','2017-04-06','2017-04-07','2017-04-08','2017-04-09'],'WeekDate':['2017-04-05','2017-04-06','2017-04-07','2017-04-07','2017-04-07']} 
import pandas as pd 
df = pd.DataFrame(raw_data,columns=['AllDate','WeekDate']) 
print df 

任何想法如何，我可以做到這一點？

Answer 1

嘗試：

import pandas as pd 
import time 

df = pd.DataFrame({ 
    'AllDate':['2017-04-05','2017-04-06','2017-04-07','2017-04-08','2017-04-09'] 
}) 
df['WeekDate'] = [ 
    x if x.weekday() not in [5,6] else None for x in pd.to_datetime(df['AllDate']) 
] 
print(df.ffill()) 

Answer 2

這個工作最好（增加張貼哲的答案）：

import pandas as pd 
import time 
from datetime import datetime,timedelta 
df = pd.DataFrame({'AllDate':['2017-04-05','2017-04-06','2017-04-07','2017-04-08','2017-04-09']}) 
df['WeekDate'] = [x if x.weekday() not in [5,6] else x - timedelta(days = (x.weekday()-4)) for x in pd.to_datetime(df['AllDate'])]