Convert a python dataframe with multiple rows into one row using python pandas?

Question

Having the following dataframe,

df = pd.DataFrame({\'device_id\' : [\'0\',\'0\',\'1\',\'1\',\'2\',\'2\'],
               \'p_food\'    : [0.2,0.1,0.3,0.5,0.1,0.7         


        

Answer 1

If you are still looking for an answer using groupby

df = df.groupby('device_id')['p_food', 'p_phone'].apply(lambda x: pd.DataFrame(x.values)).unstack().reset_index()
df.columns = df.columns.droplevel()
df.columns = ['device_id','p_food_1', 'p_food_2', 'p_phone_1','p_phone_2']

You get

    device_id   p_food_1    p_food_2    p_phone_1   p_phone_2
0   0           0.2         0.1         0.8         0.9
1   1           0.3         0.5         0.7         0.5
2   2           0.1         0.7         0.9         0.3