BucketSampler增加一条错误检测

fastNLP/core/sampler.py

@@ -73,6 +73,7 @@ class BucketSampler(BaseSampler):
         total_sample_num = len(seq_lens)
 
         bucket_indexes = []
+        assert total_sample_num>=self.num_buckets, "The number of samples is smaller than the number of buckets."
         num_sample_per_bucket = total_sample_num // self.num_buckets
         for i in range(self.num_buckets):
             bucket_indexes.append([num_sample_per_bucket * i, num_sample_per_bucket * (i + 1)])