fix: from_string method of blob and bucket class

google/cloud/storage/blob.py

@@ -330,15 +330,15 @@ def public_url(self):
         )
 
     @classmethod
-    def from_string(cls, uri, client):
+    def from_string(cls, uri, client=None):
         """Get a constructor for blob object by URI.
 
          :type uri: str
          :param uri: The blob uri pass to get blob object.
 
          :type client: :class:`~google.cloud.storage.client.Client` or
                       ``NoneType``
-         :param client: The client to use.
+         :param client: (Optional) The client to use.
 
          :rtype: :class:`google.cloud.storage.blob.Blob`
          :returns: The blob object created.
@@ -1598,6 +1598,7 @@ def _do_multipart_upload(
         :raises: :exc:`ValueError` if ``size`` is not :data:`None` but the
                  ``stream`` has fewer than ``size`` bytes remaining.
         """
+        client = self._require_client(client)
         if size is None:
             data = stream.read()
         else:
@@ -1611,7 +1612,7 @@ def _do_multipart_upload(
         headers, object_metadata, content_type = info
 
         base_url = _MULTIPART_URL_TEMPLATE.format(
-            hostname=self.client._connection.API_BASE_URL, bucket_path=self.bucket.path
+            hostname=client._connection.API_BASE_URL, bucket_path=self.bucket.path
         )
         name_value_pairs = []
 
@@ -1768,6 +1769,7 @@ def _initiate_resumable_upload(
               that was created
             * The ``transport`` used to initiate the upload.
         """
+        client = self._require_client(client)
         if chunk_size is None:
             chunk_size = self.chunk_size
             if chunk_size is None:
@@ -1780,7 +1782,7 @@ def _initiate_resumable_upload(
             headers.update(extra_headers)
 
         base_url = _RESUMABLE_URL_TEMPLATE.format(
-            hostname=self.client._connection.API_BASE_URL, bucket_path=self.bucket.path
+            hostname=client._connection.API_BASE_URL, bucket_path=self.bucket.path
         )
         name_value_pairs = []
 

google/cloud/storage/bucket.py

@@ -612,15 +612,15 @@ def user_project(self):
         return self._user_project
 
     @classmethod
-    def from_string(cls, uri, client):
+    def from_string(cls, uri, client=None):
         """Get a constructor for bucket object by URI.
 
         :type uri: str
         :param uri: The bucket uri pass to get bucket object.
 
         :type client: :class:`~google.cloud.storage.client.Client` or
                       ``NoneType``
-        :param client: The client to use.
+        :param client: (Optional) The client to use.
 
         :rtype: :class:`google.cloud.storage.bucket.Bucket`
         :returns: The bucket object created.

google/cloud/storage/client.py

@@ -579,7 +579,7 @@ def download_blob_to_file(self, blob_or_uri, file_obj, start=None, end=None):
         try:
             blob_or_uri.download_to_file(file_obj, client=self, start=start, end=end)
         except AttributeError:
-            blob = Blob.from_string(blob_or_uri, self)
+            blob = Blob.from_string(blob_or_uri)
             blob.download_to_file(file_obj, client=self, start=start, end=end)
 
     def list_blobs(

tests/unit/test_blob.py

@@ -1974,6 +1974,7 @@ def test__do_multipart_upload_with_generation_not_match(self, mock_get_boundary)
 
     def test__do_multipart_upload_bad_size(self):
         blob = self._make_one(u"blob-name", bucket=None)
+        client = mock.Mock()
 
         data = b"data here hear hier"
         stream = io.BytesIO(data)
@@ -1982,7 +1983,7 @@ def test__do_multipart_upload_bad_size(self):
 
         with self.assertRaises(ValueError) as exc_info:
             blob._do_multipart_upload(
-                None, stream, None, size, None, None, None, None, None, None
+                client, stream, None, size, None, None, None, None, None, None
             )
 
         exc_contents = str(exc_info.exception)