有没有办法将列转置为行，每行删除前一行的第一个值并插入一个新的尾值？

Question

Is there a way to transpose a column into rows with each row having the first value from the previous row deleted and a new tail value inserted such that the second value(value in second column in that row) from the previous row becomes first value(value in the first column in that row) in the next row. The resulting table has values in a sliding window fashion as they move from row to row until they are popped out of the table. I have used the Index function in Excel but it is tiresome as i have to update it for each new row and I have around 2000 rows to create. Thanks What I have done so far in the Excel =INDEX($A:$A,ROW(A1)*22-12+COLUMN(A1)) I have to update the number 22 for each new row up until 2000 and flash fill the rows manually.

Answer 1

You want to do it in postgres, or eg pandas? In pandas, you could do sth like this:

df = pd.DataFrame({'a':np.arange(10)})  # a is your original data-series

for shift in range(1,df.shape[0]):
    df[shift] = df['a'].shift(-shift)

print(df)

   a    1    2    3    4    5    6    7    8    9
0  0  1.0  2.0  3.0  4.0  5.0  6.0  7.0  8.0  9.0
1  1  2.0  3.0  4.0  5.0  6.0  7.0  8.0  9.0  NaN
2  2  3.0  4.0  5.0  6.0  7.0  8.0  9.0  NaN  NaN
3  3  4.0  5.0  6.0  7.0  8.0  9.0  NaN  NaN  NaN
4  4  5.0  6.0  7.0  8.0  9.0  NaN  NaN  NaN  NaN
5  5  6.0  7.0  8.0  9.0  NaN  NaN  NaN  NaN  NaN 
6  6  7.0  8.0  9.0  NaN  NaN  NaN  NaN  NaN  NaN
....