从 Pandas 数据框中获取每个客户的最新数据

Question

I am trying to get the latest data for every customer regardless of other attributes in the dataframe.

My dataframe looks like this

My output should look like this

I have tried 'df.iloc[df.groupby('customer')['date'].idxmax()]' but I am getting ValueError.

"ValueError Traceback (most recent call last) in ----> 1 df = df.iloc[df.groupby('cutomer')['date'].idxmax()]

~\\Anaconda3\\envs\\myenv\\lib\\site-packages\\pandas\\core\\groupby\\groupby.py in wrapper(*args, **kwargs) 653 if self.obj.ndim == 1: 654 # this can be called recursively, so need to raise ValueError --> 655 raise ValueError 656 657 # GH#3688 try to operate item-by-item

ValueError: "

Answer 1

I think it's really the same as this one: similar problem
In this case the code would look like this:

df['date'] = pd.to_datetime(df.date)
idx = df.groupby('Customer')['date'].transform(max) == df['date']
df[idx]