python - keras中填充整数和字符串的区别

Question

我正在尝试为 seq2seq 模型填充文本。

from keras_preprocessing.sequence import pad_sequences

x=[["Hello, I'm Bhaskar", "This is Keras"], ["This is an", "experiment"]]
pad_sequences(sequences=x, maxlen=5, dtype='object', padding='pre', value="<PAD>")

我遇到以下错误:

ValueError: `dtype` object is not compatible with `value`'s type: <class 'str'>
You should set `dtype=object` for variable length strings.

但是，当我尝试对整数执行相同操作时，效果很好。

x=[[1, 2, 3], [4, 5, 6]]
pad_sequences(sequences=x, maxlen=5, padding='pre', value=0)

Output:
array([[0, 0, 1, 2, 3],
       [0, 0, 4, 5, 6]], dtype=int32)

我希望得到的输出为:

[["<PAD>", "<PAD>", "<PAD>", "Hello, I'm Bhaskar", "This is Keras"], ["<PAD>", "<PAD>","<PAD>", "This is an", "experiment"]]

Answer 1

根据错误的建议，将dtype更改为object(不是字符串，而是对象本身)，它会为您完成这项工作。

from keras.preprocessing.sequence import pad_sequences

x=[["Hello, I'm Bhaskar", "This is Keras"], ["This is an", "experiment"]]
pad_sequences(sequences=x, maxlen=5, dtype=object, padding='pre', value="<PAD>")

输出

array([['<PAD>', '<PAD>', '<PAD>', "Hello, I'm Bhaskar", 'This is Keras'],
       ['<PAD>', '<PAD>', '<PAD>', 'This is an', 'experiment']],
      dtype=object)