# Add Numpy array into other Numpy array

Hi experts!!

My code starts with a empty array (POPOPO=np.array([])).

In the next lines, np.array are created (L1, L2, ...). How can it add this new-created-arrays into POPOPO in order to obtain the array POPOPO= [[L1],[L2],...]? Its important to note that L1, L2,.... have different lenght.

edit retag close merge delete

Hello mresimulator, what type of arrays are the L1, L2,.. are they one-dimensional? btw, did you solve the problem already?

Sort by » oldest newest most voted

Hello,

I do not know, if this construction is useful, but you could do the following:

 import numpy as np

L1 = np.array( [1,2] )
L2 = np.array( [1,2,3] )
L3 = np.array( [3,2,2,3] )

L = np.array( [L1, L2, L3], dtype=object )

L # will return array([1, 2])


if the number of the basic arrays are not known or is variable,
you could compose a command string and then use

count = 3
cmdstr = "L = np.array(["
for i in range(1, count):   cmdstr = cmdstr+ 'L'+str(i)+','
cmdstr = cmdstr+ 'L'+str(count)
cmdstr = cmdstr+"], dtype=object)"
cmdstr # : 'L = np.array([L1,L2,L3], dtype=object)'

exec(cmdstr) # L will be = array([[1 2], [1 2 3], [3 2 2 3]], dtype=object)


Remark: it did'nt work neither with np.concatenate nor with np.append

more