Conditionally Binning

Is it possible to create a new column in a dataframe where the bins for 'X' are based on a value of another column(s). Example below. The bins for AR1, PO1 and RU1 are different f

Solution 1:

Simple use pd.qcut within a groupby on S

df['bins_X'] = df.groupby('S').X.apply(pd.qcut, q=10, labels=np.arange(10))

df.groupby(['bins_X', 'S']).size().unstack()

S       AR1  PO1  RU1
bins_X               
0         3    4    4
1         3    3    4
2         3    3    4
3         2    3    4
4         3    4    4
5         3    3    3
6         2    3    4
7         3    3    4
8         3    3    4
9         3    4    4

Leave of the labels parameter if you want them to have their own unique edges

df['bins_X'] = df.groupby('S').X.apply(pd.qcut, q=10)