python - Pandas sorting dataframe on the basis of other column value -

i have sorted pandas dataframe df.

i use df = df.sort(col_a,col_b)

 col_a col_b         6              7              8             11               b     5          b     10    b     12    c     11          c     13          c     14      

but i'd sort df on basis of col_b min , max value have in first place col_a value min col_b value , @ last place col_a value max col_b value :

 col_a col_b          b     5          b     10    b     12        6              7              8              11          c     11          c     13          c     14     

is there fast way make kind of sorting using pandas fucntion?

edit 1:

@primer solution works 2 columns df. df

    col_a  col_b  col_c 0          6      9 1          7      8 2          8      7 3         11      6 4     b      5      5 5     b     10      4 6     b     12      3 7     c     11      2 8     c     13      1 9     c     14      0 

return

valueerror: wrong number of items passed 2, placement implies 1 

edit 2

d = {'col_a' : ['a','a','a','a','b','b','c','c','c'],     'col_b' :[6,7,8,11,12,13,11,13,14],     'col_c' :[9,8,7,6,5,4,3,2,1]     }  df = dataframe(d) 

return:

  col_a  col_b  col_c 0          6      9 1          7      8 2          8      7 3         11      6 4     b     12      5 5     b     13      4 6     c     11      3 7     c     13      2 8     c     14      1 

@primer whit df code doesnt'work because returns:

  col_a  col_b  col_c 0          6      9 1          7      8 2          8      7 3         11      6 4     c     11      3 5     c     13      2 6     c     14      1 7     b     12      5 8     b     13      4 

i need have

  col_a  col_b  col_c 0          6      9 1          7      8 2          8      7 3         11      6 4     b     12      5 5     b     13      4 6     c     11      3 7     c     13      2 8     c     14      1 

because c group has max(value)=14,instead code takes max(min) values

you this:

df['min'] = df.groupby('col_a')['col_b'].transform(lambda x: x.min()) df = df.sort(['min', 'col_a', 'col_b']).reset_index(drop=true).drop('min', 1) df 

which yields:

  col_a  col_b 0     b      5 1     b     10 2     b     12 3          6 4          7 5          8 6         11 7     c     11 8     c     13 9     c     14 

edit:

i have fixed code above make sure transform used on series , not on dataframe (thus avoiding error).

works me returning:

  col_a  col_b  col_c 0     b      5      5 1     b     10      4 2     b     12      3 3          6      9 4          7      8 5          8      7 6         11      6 7     c     11      2 8     c     13      1 9     c     14      0 

i guess turn function apply on dataframe inplace.