How to one-hot-encode sentences at the character level?

Question

I would like to convert a sentence to an array of one-hot vector. These vector would be the one-hot representation of the alphabet. It would look like the following:

Answer 1

You asked about "sentences" but your example provided only a single word, so I'm not sure what you wanted to do about spaces. But as far as single words are concerned, your example could be implemented with:

def onehot(ltr):
 return [1 if i==ord(ltr) else 0 for i in range(97,123)]

def onehotvec(s):
 return [onehot(c) for c in list(s.lower())]

onehotvec("hello")
[[0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
 [0, 0, 0, 0, 1, 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, 0, 0, 0, 0, 1, 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, 1, 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, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]]