How to create dummies for certain columns with pandas.get_dummies()

df = pd.DataFrame({'A': ['x', 'y', 'x'], 'B': ['z', 'u', 'z'],
                  'C': ['1', '2', '3'],
                  'D':['j', 'l', 'j']})

I just want Column A and D to get dummies not for Column B. If I used pd.get_dummies(df), all columns turned into dummies.

I want the final result containing all of columns , which means column C and column B exit,like 'A_x','A_y','B','C','D_j','D_l'.

Answer

It can be done without concatenation, using get_dummies() with required parameters

In [294]: pd.get_dummies(df, prefix=['A', 'D'], columns=['A', 'D'])
Out[294]: 
   B  C  A_x  A_y  D_j  D_l
0  z  1  1.0  0.0  1.0  0.0
1  u  2  0.0  1.0  0.0  1.0
2  z  3  1.0  0.0  1.0  0.0