import mindspore.dataset as ds
import numpy as np
class MyAccessible:
    def __init__(self):
        self._data = np.arange(0,40).reshape(20,2)
        self._label = np.arange(40,60).reshape(20,1)
    def __getitem__(self, index):
        return self._data[index], self._label[index]
    def __len__(self):
        return len(self._data)
    
class MySampler(ds.Sampler):
    def __iter__(self):
        for i in range(0, 10, 2):
            yield str(i)
            
sampler = ds.IterSampler(sampler=MySampler())
dataset = ds.GeneratorDataset(source=MyAccessible(), column_names=["data", "label"],sampler=sampler)
for i in dataset:
    print(i)

RuntimeError                              Traceback (most recent call last)
Cell In [167], line 19
     17 sampler = ds.IterSampler(sampler=MySampler())
     18 dataset = ds.GeneratorDataset(source=MyAccessible(), column_names=["data", "label"],sampler=sampler)
---> 19 for i in dataset:
     20     print(i)

File D:\Anaconda\envs\ms\lib\site-packages\mindspore\dataset\engine\iterators.py:141, in Iterator.__next__(self)
    138     raise RuntimeError("Iterator does not have a running C++ pipeline.")
    140 # Note offload is applied inside _get_next() if applicable since get_next converts to output format
--> 141 data = self._get_next()
    142 if not data:
    143     if self.__index == 0:

File D:\Anaconda\envs\ms\lib\site-packages\mindspore\dataset\engine\iterators.py:253, in TupleIterator._get_next(self)
    245 """
    246 Returns the next record in the dataset as a list
    247 
    248 Returns:
    249     List, the next record in the dataset.
    250 """
    252 if self.offload_model is None:
--> 253     return [self._transform_md_to_output(t) for t in self._iterator.GetNextAsList()]
    254 data = [self._transform_md_to_tensor(t) for t in self._iterator.GetNextAsList()]
    255 if data:

RuntimeError: Unexpected error. TypeCast: TypeCast does not support cast from string to int64
Line of code : 369
File         : mindspore\ccsrc\minddata\dataset\kernels\data\data_utils.cc