How can I put into a 2D array a list of binary string

Question

I have a binary list of string numbers as following:

['0b111',
 '0b1110011',
 '0b1110100',
 '0b11101001',
 '0b1100111',
 '0b1100001',
 '0b1101110',
 '0b1101111']

And I would like to put this list into a 2D array of integers as following:

array([[0, 0, 0, 0, 0, 1, 1, 1],
 [0, 1, 1, 1, 0, 0, 1, 1],
 [0, 1, 1, 1, 0, 1, 0, 0],
 [1, 1, 1, 0, 1, 0, 0, 1],
 [0, 1, 1, 0, 0, 1, 1, 1],
 [0, 1, 1, 0, 0, 0, 0, 1],
 [0, 1, 1, 0, 1, 1, 1, 0],
 [0, 1, 1, 0, 1, 1, 1, 1]], dtype=uint8)

I have first removed the '0b' of the binary sequences and put it in the res list. Then I've created a 2D array in order to put my list into it. And I have tried to do a double loop but I'm a bit confusing with it :

 res = []
 for i in range(len(conv_bin)):
 res.append(conv_bin[i][2:])
 arr = np.array(res)
 arr2 = np.zeros((8,8))
 for i in range(arr.shape[0]):
 for j in range(arr2.shape[0]):
 arr2[i] = arr[j]

Answer 1

You can use the numpy unpackbits function to help.

import numpy as np
conv_bin = ['0b111',
 '0b1110011',
 '0b1110100',
 '0b11101001',
 '0b1100111',
 '0b1100001',
 '0b1101110',
 '0b1101111']
np.unpackbits(np.array([[int(s,2)] for s in conv_bin], dtype=np.uint8), axis=1)

Answer 2

If you want to use for loops you can use this:

import numpy as np
conv_bin=['0b111',
 '0b1110011',
 '0b1110100',
 '0b11101001',
 '0b1100111',
 '0b1100001',
 '0b1101110',
 '0b1101111']
res =[]
for string in conv_bin:
 ls=[]
 string=string[2:]
 for ch in string:
 ls.append(ch)
 res.append(ls)

Answer 3

• I think you can avoid the creation of multiple new lists like res and arr2 as well with the solution I'm writing below.
• A simple solution would be to traverse the binary matrix in reverse order

arr2 = np.zeros((8,8))
for i in range(len(conv_bin)):
 '''
 1. zip is function is to loop across two variables in this for loop
 2. j is traversing each binary in the reverse order only until the 2nd index, 
 3. k is used to index the resultant array from reverse (we need different variables since the index values differ)
 '''
 for j,k in zip(range(len(conv_bin[i])-1, 1, -1), range(-1,-9,-1 )):
 arr2[i][k] = conv_bin[i][j]

PS - In case you didn't know, in python you can index array from the reverse like this:
arr[-1] -> last element of array
arr[-2] -> last but one element
arr[-3] -> last but two elements and so on

Hope I've been clear in my answer