Python appending array to an array

Question

I am currently working on DES implementation.In one part of the code I have to append array to an array.Below is my code:

C0=[1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 1, 1, 1]  def Fiestel():     C=[]     C.append(C0)     temp=[0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 1, 1, 0, 0, 0, 1, 1, 1, 1]     C.append(temp)     print(C) Fiestel() 

How do I append an array to an existing array.I even tried declaring C as 2d array.Thankx in advance for helping.

Each element is an array itself.

Answer 1

You can append the elements of one list to another with the "+=" operator. Note that the "+" operator creates a new list.

a = [1, 2, 3] b = [10, 20]  a = a + b # Create a new list a+b and assign back to a. print a # [1, 2, 3, 10, 20]   # Equivalently: a = [1, 2, 3] b = [10, 20]  a += b print a # [1, 2, 3, 10, 20] 

If you want to append the lists and keep them as lists, then try:

result = [] result.append(a) result.append(b) print result # [[1, 2, 3], [10, 20]]