Error when using viterbi_decode of tensorflow - tensorflow

Question

I am using this github.com/Determined22/zh-NER-TF
I just used another train_data of the same format.
Nothing is wrong with the code because it's okay when I run with the original train_data. What can cause this?
Traceback (most recent call last):
File "main.py", line 83, in <module>
model.train(train=train_data, dev=dev_data)
File "/home/mengyuguang/NER/model.py", line 161, in train
self.run_one_epoch(sess, train, dev, self.tag2label, epoch, saver)
File "/home/mengyuguang/NER/model.py", line 221, in run_one_epoch
label_list_dev, seq_len_list_dev = self.dev_one_epoch(sess, dev)
File "/home/mengyuguang/NER/model.py", line 256, in dev_one_epoch
label_list_, seq_len_list_ = self.predict_one_batch(sess, seqs)
File "/home/mengyuguang/NER/model.py", line 277, in predict_one_batch
viterbi_seq, _ = viterbi_decode(logit[:seq_len], transition_params)
File "/usr/local/lib/python2.7/dist-packages/tensorflow/contrib/crf/python/ops/crf.py", line 333, in viterbi_decode
trellis[0] = score[0]
IndexError: index 0 is out of bounds for axis 0 with size 0

Answer 1

def read_corpus(self, corpus_path):
data = []
with open(corpus_path, 'r') as r_file:
sent_, tag_ = [], []
for line in r_file:
line = line.strip()
if len(line) != 0 and line != '-DOCSTART-':
ls = line.split('\t')
char, tag = ls[0], ls[-1]
sent_.append(char)
tag_.append(tag)
else:
data.append((sent_, tag_))
sent_, tag_ = [], []
# Bug-fix
# Here, since the last tuple (sent_, tag_) will be added into data
# It will case IndexError in viterbi_decode since the sequence_length is 0
if sent_ and tag_:
data.append((sent_, tag_))
self.data = data

Answer 2

The code should be changed to the following:
def read_corpus(corpus_path):
"""
read corpus and return the list of samples
:param corpus_path:
:return: data
"""
data = []
with open(corpus_path, encoding='utf-8') as fr:
lines = fr.readlines()
sent_, tag_ = [], []
for line in lines:
if line != '\n' and line != '\t\n': #
[char, label] = line.strip().split()
sent_.append(char)
tag_.append(label)
#else:
elif sent_ !=[] and tag_ !=[]: #
data.append((sent_, tag_))
sent_, tag_ = [], []
return data