add is not none

gcsfs/core.py

@@ -1,6 +1,7 @@
 """
 Google Cloud Storage pythonic interface
 """
+
 import asyncio
 import io
 import json
@@ -142,8 +143,9 @@ def _coalesce_generation(*args):
         generations.remove(None)
     if len(generations) > 1:
         raise ValueError(
-            "Cannot coalesce generations where more than one are defined,"
-            " {}".format(generations)
+            "Cannot coalesce generations where more than one are defined," " {}".format(
+                generations
+            )
         )
     elif len(generations) == 0:
         return None
@@ -285,7 +287,7 @@ def __init__(
         version_aware=False,
         **kwargs,
     ):
-        if cache_timeout:
+        if cache_timeout is not None:
             kwargs["listings_expiry_time"] = cache_timeout
         super().__init__(
             self,