Won't the code leads to different input shape for different batch?

[MingleiLI]

In the file data_util.py, the code is as follows:
`def batch(inputs):
batch_size = len(inputs)

document_sizes = np.array([len(doc) for doc in inputs], dtype=np.int32) # Different batch will
# have different document_sizes.
document_size = document_sizes.max() # Document with maximum sentence number.

sentence_sizes_ = [[len(sent) for sent in doc] for doc in inputs] # every sentence len in each document.
sentence_size = max(map(max, sentence_sizes_)) # The maximum sentence length.

b = np.zeros(shape=[batch_size, document_size, sentence_size], dtype=np.int32) # == PAD

sentence_sizes = np.zeros(shape=[batch_size, document_size], dtype=np.int32)
for i, document in enumerate(inputs):
for j, sentence in enumerate(document):
sentence_sizes[i, j] = sentence_sizes_[i][j]
for k, word in enumerate(sentence):
b[i, j, k] = word

return b, document_sizes, sentence_sizes`
The output batch depends on the inputs. Won't this leads to different shapes of b since the input is not padded before. Each document may have different number of sentences and each sentence may have different number words.