熊猫DENSE RANK

问题描述：

我正在处理pandas数据框，并具有如下所示的框:

I'm dealing with pandas dataframe and have a frame like this:

我想使DENSE_RANK()等价于(按年排序)函数.像这样增加一列:

I want to make an equialent to DENSE_RANK () over (order by year) function. to make an additional column like this:

    Year Value Rank
    2012  10    1
    2013  20    2
    2013  25    2
    2014  30    3

在大熊猫中怎么做?

谢谢！

答

将pd.Series.rank与method='dense'

df['Rank'] = df.Year.rank(method='dense').astype(int)

df