Added blob exists method

sdk/storage/azure-storage-blob/azure/storage/blob/_blob_client.py

@@ -919,7 +919,7 @@ def undelete_blob(self, **kwargs):
             process_storage_error(error)
 
     @distributed_trace()
-    def exists(self, timeout=None, version_id=None):
+    def exists(self, **kwargs):
         # type: (**Any) -> bool
         """
         Returns True if a blob exists with the defined parameters, and returns
@@ -933,10 +933,14 @@ def exists(self, timeout=None, version_id=None):
         :returns: boolean
         """
         try:
-            self._client.blob.get_properties(
-                timeout=timeout,
-                version_id=version_id)
-            return True
+            blob_props = self._client.blob.get_properties(
+                timeout=kwargs.pop('timeout', None),
+                version_id=kwargs.pop('version_id', None),
+                snapshot=self.snapshot,
+                cls=deserialize_blob_properties)
+            if blob_props and blob_props.is_current_version or blob_props and self.snapshot:
+                return True
+            return False
         except StorageErrorException:
             return False
 

sdk/storage/azure-storage-blob/azure/storage/blob/aio/_blob_client_async.py

@@ -460,6 +460,32 @@ async def undelete_blob(self, **kwargs):
         except StorageErrorException as error:
             process_storage_error(error)
 
+    @distributed_trace_async
+    async def exists(self, **kwargs):
+        # type: (**Any) -> bool
+        """
+        Returns True if a blob exists with the defined parameters, and returns
+        False otherwise.
+
+        :param str version_id:
+            The version id parameter is an opaque DateTime
+            value that, when present, specifies the version of the blob to check if it exists.
+        :param int timeout:
+            The timeout parameter is expressed in seconds.
+        :returns: boolean
+        """
+        try:
+            blob_props = await self._client.blob.get_properties(
+                timeout=kwargs.pop('timeout', None),
+                version_id=kwargs.pop('version_id', None),
+                snapshot=self.snapshot,
+                cls=deserialize_blob_properties)
+            if blob_props and blob_props.is_current_version or blob_props and self.snapshot:
+                return True
+            return False
+        except StorageErrorException:
+            return False
+
     @distributed_trace_async
     async def get_blob_properties(self, **kwargs):
         # type: (Any) -> BlobProperties