python深度学习 代码清单6-2错误

# 错误代码
import string

samples = ['The cat sat on the mat.', 'The dog ate my homework.']
characters = string.printable
token_index = dict(zip(range(1, len(characters) + 1), characters))

max_length = 50
results = np.zeros((len(samples), max_length, max(token_index.keys()) + 1))
for i, sample in enumerate(samples):
    for j, character in enumerate(sample):
        index = token_index.get(character)
        results[i, j, index] = 1.

# 正确代码
import string

samples = ['The cat sat on the mat.', 'The dog ate my homework.']
characters = string.printable  # All printable ASCII characters.
token_index = dict(zip(characters, range(1, len(characters) + 1)))

max_length = 50
results = np.zeros((len(samples), max_length, max(token_index.values()) + 1))
for i, sample in enumerate(samples):
    for j, character in enumerate(sample[:max_length]):
        index = token_index.get(character)
        results[i, j, index] = 1.

按照原书中代码，得到的results不是one-hot向量。