Convert pandas dateframe from row to column

Question

I have the following data frame:

ID	value	freq
A	a	0.1
A	b	0.12
A	c	0.19
B	a	0.15
B	b	0.2
B	c	0.09
C	a	0.39
C	b	0.15
C	c	0.01

and I would like to get the following

ID	freq_a	freq_b	freq_c
A	0.1	0.12	0.19
B	0.15	0.2	0.09
C	0.39	0.15	0.01

Any ideas how to easily do this?

Answer 1

using pivot:

df.pivot(index='ID', columns='value', values='freq').add_prefix('freq_').reset_index()

output:

>>
value ID  freq_a  freq_b  freq_c
0      A    0.10    0.12    0.19
1      B    0.15    0.20    0.09
2      C    0.39    0.15    0.01

Answer 2

Use pivot_table:

out = df.pivot_table('freq', 'ID', 'value').add_prefix('freq_') \
        .rename_axis(columns=None).reset_index()
print(out)

# Output
  ID  freq_a  freq_b  freq_c
0  A    0.10    0.12    0.19
1  B    0.15    0.20    0.09
2  C    0.39    0.15    0.01