raise FileNotFoundError if file isn't found

swiftspec/core.py

@@ -211,6 +211,14 @@ async def _ls(self, path, detail=True, **kwargs):
 
     ls = sync_wrapper(_ls)
 
+    def _raise_not_found_for_status(self, response, ref):
+        """
+        Raises FileNotFoundError for 404s, otherwise uses raise_for_status.
+        """
+        if response.status == 404:
+            raise FileNotFoundError(ref.swift_url)
+        response.raise_for_status()
+
     async def _cat_file(self, path, start=None, end=None, **kwargs):
         ref = SWIFTRef(path)
         headers = self.headers_for_url(ref.http_url)
@@ -228,7 +236,7 @@ async def _cat_file(self, path, start=None, end=None, **kwargs):
 
         session = await self.set_session()
         async with session.get(ref.http_url, headers=headers) as res:
-            res.raise_for_status()
+            self._raise_not_found_for_status(res, ref)
             return await res.read()
 
     async def _pipe_file(self, path, data, chunksize=50 * 2 ** 20, **kwargs):

test/test_swiftfilesystem.py

@@ -214,6 +214,11 @@ def test_cat(fs):
     assert fs.cat("swift://server/a1/c1/hello") == b"Hello World"
 
 
+def test_cat_raises_not_found(fs):
+    with pytest.raises(FileNotFoundError):
+        assert fs.cat("swift://server/a1/c1/doesnt_exist")
+
+
 def test_cat_partial(fs):
     assert fs.cat("swift://server/a1/c1/hello", start=3, end=5) == b"lo"