fix: avoid triggering global logging config (#333)

Closes #332

Author: tseaver

google/cloud/storage/blob.py

@@ -122,6 +122,8 @@
 _DEFAULT_CHUNKSIZE = 104857600 # 1024 * 1024 B * 100 = 100 MB
 _MAX_MULTIPART_SIZE = 8388608 # 8 MB
 
+_logger = logging.getLogger(__name__)
+
 
 class Blob(_PropertyMixin):
  """A wrapper around Cloud Storage's concept of an ``Object``.
@@ -923,7 +925,7 @@ def _do_download(
 
  if checksum:
  msg = _CHUNKED_DOWNLOAD_CHECKSUM_MESSAGE.format(checksum)
- logging.info(msg)
+ _logger.info(msg)
 
  if raw_download:
  klass = RawChunkedDownload

tests/unit/test_blob.py

@@ -1115,7 +1115,7 @@ def test__do_download_w_chunks_w_custom_timeout(self):
  def test__do_download_w_chunks_w_checksum(self):
  from google.cloud.storage import blob as blob_module
 
- with mock.patch("logging.info") as patch:
+ with mock.patch.object(blob_module._logger, "info") as patch:
  self._do_download_helper_w_chunks(
  w_range=False, raw_download=False, checksum="md5"
  )
@@ -1124,7 +1124,9 @@ def test__do_download_w_chunks_w_checksum(self):
  )
 
  def test__do_download_w_chunks_wo_checksum(self):
- with mock.patch("logging.info") as patch:
+ from google.cloud.storage import blob as blob_module
+
+ with mock.patch.object(blob_module._logger, "info") as patch:
  self._do_download_helper_w_chunks(
  w_range=False, raw_download=False, checksum=None
  )