I have a small array..
lot_id S1 S2 S3 S4
1 A 1 2 3 4
2 A 5 6 7 8
3 A 9 10 11 12
4 B 13 14 15 16
5 B 17 18 19 20
6 B 21 22 23 24
7 C 25 26 27 28
8 C 29 30 31 32
9 C 33 34 35 36
10 D 37 38 39 40
11 D 41 42 43 44
12 D 45 46 47 48
13 E 49 50 51 52
14 E 53 54 55 56
15 E 57 58 59 60
16 F 61 62 63 64
17 F 65 66 67 68
18 F 69 70 71 72
19 G 73 74 75 76
20 G 77 78 79 80
21 G 81 82 83 84
I'm looping over by lot_id and selecting that subset of data then adding it to a new list - however the behaviour is strange. When i view the list at the end it only seems to store the last lot-id element ith times..?
The list should contain this...
A
(10, 4)
[[ 1. 2. 3. 4.]
[ 5. 6. 7. 8.]
[ 9. 10. 11. 12.]
[ 0. 0. 0. 0.]
[ 0. 0. 0. 0.]
[ 0. 0. 0. 0.]
[ 0. 0. 0. 0.]
[ 0. 0. 0. 0.]
[ 0. 0. 0. 0.]
[ 0. 0. 0. 0.]]
B
(10, 4)
[[13. 14. 15. 16.]
[17. 18. 19. 20.]
[21. 22. 23. 24.]
[ 0. 0. 0. 0.]
[ 0. 0. 0. 0.]
[ 0. 0. 0. 0.]
[ 0. 0. 0. 0.]
[ 0. 0. 0. 0.]
[ 0. 0. 0. 0.]
[ 0. 0. 0. 0.]]
C
(10, 4)
[[25. 26. 27. 28.]
[29. 30. 31. 32.]
[33. 34. 35. 36.]
[ 0. 0. 0. 0.]
[ 0. 0. 0. 0.]
[ 0. 0. 0. 0.]
[ 0. 0. 0. 0.]
[ 0. 0. 0. 0.]
[ 0. 0. 0. 0.]
[ 0. 0. 0. 0.]]
And so on...... But it actually contains this...
[array([[73., 74., 75., 76.],
[77., 78., 79., 80.],
[81., 82., 83., 84.],
[ 0., 0., 0., 0.],
[ 0., 0., 0., 0.],
[ 0., 0., 0., 0.],
[ 0., 0., 0., 0.],
[ 0., 0., 0., 0.],
[ 0., 0., 0., 0.],
[ 0., 0., 0., 0.]]), array([[73., 74., 75., 76.],
[77., 78., 79., 80.],
[81., 82., 83., 84.],
[ 0., 0., 0., 0.],
[ 0., 0., 0., 0.],
[ 0., 0., 0., 0.],
[ 0., 0., 0., 0.],
[ 0., 0., 0., 0.],
[ 0., 0., 0., 0.],
[ 0., 0., 0., 0.]]), array([[73., 74., 75., 76.],
[77., 78., 79., 80.],
[81., 82., 83., 84.],
[ 0., 0., 0., 0.],
[ 0., 0., 0., 0.],
[ 0., 0., 0., 0.],
[ 0., 0., 0., 0.],
[ 0., 0., 0., 0.],
[ 0., 0., 0., 0.],
I'm, zero padding during the loop too...
Heres the code..
lotids = dummy['lot_id'].unique()
temp = np.zeros(shape=(10,4)) #template to pad to
lsttest2 = [] #define empty list
lots = len(lotids)
for i in range(lots):
lot = lotids[i]
lotsub = dummy[dummy.lot_id==lot]
lotsub = lotsub.to_numpy()
lotsub = np.delete(lotsub, 0, 1) #remove the lot_id col
temp[:lotsub.shape[0],:lotsub.shape[1]] = lotsub #add it to the all zero array to pad out
print(temp.shape)
print(temp)
lsttest2.append(temp)
print("this is the end of loop---", i, " the list now has ", len(lsttest2), " elements")
print(lsttest2)
I don't understand why the last loop element is being copied to every ith entry in the list..?
