python - Consecutive next value into new column pandas dataframe -

i have dataframe

id    value  v1      100  v1      200  v1      300  v1      400  v2      500  v2      600  v2      700  v3      800  v3      900 

i looking transform dataframe new dataframe df2:

id   val1    val2 v1     100     200 v1     200     300 v1     300     400 v1     400     100 v2     500     600 v2     600     700 v2     700     500 v3     800     900 v3     900     800 

i.e shifting next consecutive value in next column , kind of grouping id's,

i tried using df.shift() , not working.

is there alternative this?

we want use np.roll accomplish task within groups. using transform, bypass getting hung within group index.

df.groupby('id').value.transform(np.roll, shift=-1)  0    200 1    300 2    400 3    100 4    600 5    700 6    500 7    900 8    800 name: value, dtype: int64 

---

we can add new column copy of df assign

df.assign(val2=df.groupby('id').value.transform(np.roll, shift=-1))     id  value  val2 0  v1    100   200 1  v1    200   300 2  v1    300   400 3  v1    400   100 4  v2    500   600 5  v2    600   700 6  v2    700   500 7  v3    800   900 8  v3    900   800 

or add new column directly df in place

df['val2'] = df.groupby('id').value.transform(np.roll, shift=-1)  df     id  value  val2 0  v1    100   200 1  v1    200   300 2  v1    300   400 3  v1    400   100 4  v2    500   600 5  v2    600   700 6  v2    700   500 7  v3    800   900 8  v3    900   800