Fill data to array from another array

Question

I'm trying to fill an empty array with the shape that I want from a list data. I am using a for loop to do so, but it is only reading the first values and filling the whole array with them.

What I want is to fill the array every twelve numbers. For example:

list: [1,2,3, ... , 24]

array = [[1,2,...,12], [13,14,...,24]]

Here is my code:

SSTA_12_data = []
for i in range(0,len(SSTA_12)):
 SSTA_12_data.append(SSTA_12["ANOM1+2"][i])
np.shape(SSTA_12_data)
(461,)
Prueba_a = np.empty(shape=(len(Años),12)) (Años has len 39)
Prueba_a[:] = np.nan
for i in range(0,39):
 for j in range(0,12):
 Prueba_a[i,j] = SSTA_12_data[j]

and this is what I am getting:

array([[-0.17, -0.58, -1.31, -0.97, -0.23, 0.07, 0.87, 1.1 , 1.44,
 2.12, 3. , 3.34],
 [-0.17, -0.58, -1.31, -0.97, -0.23, 0.07, 0.87, 1.1 , 1.44,
 2.12, 3. , 3.34],
 [-0.17, -0.58, -1.31, -0.97, -0.23, 0.07, 0.87, 1.1 , 1.44,
 2.12, 3. , 3.34],
 [-0.17, -0.58, -1.31, -0.97, -0.23, 0.07, 0.87, 1.1 , 1.44,
 2.12, 3. , 3.34], ...]

Answer 1

If you already using numpy, you can consider using reshape. For example, if SSTA_12_data.shape is (120,), i.e. a 1D numpy array, then SSTA_12_data.reshape((-1,12)) will be of shape (10,12). In code, you can try with:

SSTA_12_data = []
for i in range(0,len(SSTA_12)):
 SSTA_12_data.append(SSTA_12["ANOM1+2"][i])
padsize = 12 - (len(SSTA_12_data) % 12)
SSTA_12_data = np.array(SSTA_12_data)
Prueba_a = np.pad(SSTA_12_data, (0, padsize)).reshape((-1,12))

• tonysg: I already try it, but this is the error that I get: ValueError: cannot reshape array of size 461 into shape (12)
• adrtam: How do you want to handle this odd ends? 461 is not divisible by 12
• tonysg: I know, thats the problem. Thats why I was trying to do it with for loops. The data is updated every month so some months the data will be odd or even.
• adrtam: Then you can try to pad the ends. Updated the answer