Get min max values of categorical variable in a dataframe

November 13, 2021

I have a dataframe that looks like this

   D   X   Y   Z
   A  22  16  23
   A  21  16  22
   A  20  17  21
   B  33  50  11
   B  34  53  12
   B  34  55  13
   C  44  34  11
   C  45  33  11
   C  45  33  10
   D  55  35  60
   D  57  34  61
   E  66  36  13
   E  67  38  14 
   E  67  37  13

I want to get the minimum and maximum values of the categorical variable ‘D’ across all the column values and so the output dataframe should look something like this

D Xmin Xmax Ymin Ymax Zmin Zmax
A 20    22   16   17   21   23 
B 33    34   50   55   11   13    
C 44    45   33   34   10   11  
D 55    57   34   35   60   61
E 66    67   36   38   13   14

I have tried this so far to capitalize upon to build the above mentioned output but no luck

min_max_df = dfObj.groupby('D').agg({'X': [dfObj.min(axis=0), dfObj.max(axis=0)]})

>Solution :

I believe this is a nice way of doing it and in a single line of code. Making use of join doing the operation by index and the rsuffix and lsuffix to differentiate min and max.

output = df.groupby('D').min().join(df.groupby('D').max(),lsuffix='min',rsuffix='max')

Outputs:

   Xmin  Xmax  Ymin  Ymax  Zmin  Zmax
D
A    20    22    16    17    21    23
B    33    34    50    55    11    13
C    44    45    33    34    10    11
D    55    57    34    35    60    61
E    66    67    36    38    13    14