Fix operations with no up or download (#192)

* Fix operations with no up or download

* Placate pylint

ibridges/data_operations.py

@@ -374,12 +374,14 @@ def perform_operations(session: Session, operations: dict, ignore_err: bool=Fals
     """
     up_sizes = [lpath.stat().st_size for lpath, _ in operations["upload"]]
     down_sizes = [ipath.size for ipath, _ in operations["download"]]
-    pbar = tqdm(total=sum(up_sizes) + sum(down_sizes), unit="B", unit_scale=True, unit_divisor=1024)
+    disable = len(up_sizes) + len(down_sizes) == 0
+    pbar = tqdm(total=sum(up_sizes) + sum(down_sizes), unit="B", unit_scale=True, unit_divisor=1024,
+                disable=disable)
 
     # For large files, the checksum computation might take too long, which can result in a timeout.
     # This is why we increase the time out from file sizes > 1 GB
     # This might still result in a time out if your server is very busy or a potato.
-    max_size = max([*up_sizes, *down_sizes])
+    max_size = max([*up_sizes, *down_sizes, 0])
     original_timeout = session.irods_session.pool.connection_timeout
     if max_size > 1e9 and original_timeout == DEFAULT_CONNECTION_TIMEOUT:
         session.irods_session.pool.connection_timeout = int(