我正在尝试获取以下代码，以将多个csv文件从Google Cloud Bucket导入python 3.x中的Datalab：
import google.datalab.storage as storage
import pandas as pd
from io import BytesIO
myBucket = storage.Bucket('some-bucket')
object_list = myBucket.objects(prefix='some-prefix')
df_list = []
for obj in object_list:
%gcs read --object $obj.uri --variable data
df_list.append(pd.read_csv(BytesIO(data), compression='gzip'))
df = pd.concat(df_list, ignore_index=True)
df.head()
我在for循环开始时收到以下错误：
TypeError: a bytes-like object is required, not 'str'
我花了一些时间解决这个问题，但没有运气！任何帮助将不胜感激！
以下是整个回溯，以防万一：
---------------------------------------------------------------------------
JSONDecodeError Traceback (most recent call last)
/usr/local/envs/py3env/lib/python3.5/site-packages/google/datalab/utils/_http.py in __init__(self, status, content)
49 else:
---> 50 error = json.loads(str(content, encoding='UTF-8'))['error']
51 if 'errors' in error:
/usr/local/envs/py3env/lib/python3.5/json/__init__.py in loads(s,
encoding, cls, object_hook, parse_float, parse_int, parse_constant,
object_pairs_hook, **kw)
318 parse_constant is None and object_pairs_hook is None and not kw):
--> 319 return _default_decoder.decode(s)
320 if cls is None:
/usr/local/envs/py3env/lib/python3.5/json/decoder.py in decode(self, s, _w)
338 """
--> 339 obj, end = self.raw_decode(s, idx=_w(s, 0).end())
340 end = _w(s, end).end()
/usr/local/envs/py3env/lib/python3.5/json/decoder.py in raw_decode(self, s, idx)
356 except StopIteration as err:
--> 357 raise JSONDecodeError("Expecting value", s, err.value) from None
358 return obj, end
JSONDecodeError: Expecting value: line 1 column 1 (char 0)
During handling of the above exception, another exception occurred:
TypeError Traceback (most recent call last)
<ipython-input-9-6d51e52b6c6f> in <module>()
7 df_list = []
8
----> 9 for obj in object_list:
10 get_ipython().run_line_magic('gcs', 'read --object $obj.uri --variable data')
11 df_list.append(pd.read_csv(BytesIO(data), compression='gzip'))
/usr/local/envs/py3env/lib/python3.5/site-packages/google/datalab/utils/_iterator.py in __iter__(self)
34 """Provides iterator functionality."""
35 while self._first_page or (self._page_token is not None):
---> 36 items, next_page_token = self._retriever(self._page_token, self._count)
37
38 self._page_token = next_page_token
/usr/local/envs/py3env/lib/python3.5/site-packages/google/datalab/storage/_object.py in _retrieve_objects(self, page_token, _)
319 page_token=page_token)
320 except Exception as e:
--> 321 raise e
322
323 objects = list_info.get('items', [])
/usr/local/envs/py3env/lib/python3.5/site-packages/google/datalab/storage/_object.py in _retrieve_objects(self, page_token, _)
317 list_info = self._api.objects_list(self._bucket,
318 prefix=self._prefix,
delimiter=self._delimiter,
--> 319 page_token=page_token)
320 except Exception as e:
321 raise e
/usr/local/envs/py3env/lib/python3.5/site-packages/google/datalab/storage/_api.py in objects_list(self, bucket, prefix, delimiter, projection, versions, max_results, page_token)
246
247 url = Api._ENDPOINT + (Api._OBJECT_PATH % (bucket, ''))
--> 248 return google.datalab.utils.Http.request(url, args=args, credentials=self._credentials)
249
250 def objects_patch(self, bucket, key, info):
/usr/local/envs/py3env/lib/python3.5/site-packages/google/datalab/utils/_http.py in request(url, args, data, headers, method, credentials, raw_response, stats)
156 return json.loads(str(content, encoding='UTF-8'))
157 else:
--> 158 raise RequestException(response.status, content)
159 except ValueError:
160 raise Exception('Failed to process HTTP response.')
/usr/local/envs/py3env/lib/python3.5/site-packages/google/datalab/utils/_http.py in __init__(self, status, content)
53 self.message += ': ' + error['message']
54 except Exception:
---> 55 lines = content.split('n') if isinstance(content, basestring) else []
56 if lines:
57 self.message += ': ' + lines[0]
TypeError: a bytes-like object is required, not 'str'
BytesIO类要求参数为字节，而不是字符串：
>>> from io import BytesIO
>>> BytesIO(b'hi')
<_io.BytesIO object at 0x1088aedb0>
>>> BytesIO('hi')
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
TypeError: a bytes-like object is required, not 'str'
如果data是字符串而不是字节，则应使用：
from io import StringIO
pd.read_csv(StringIO(data))