diff --git a/fsspec/gui.py b/fsspec/gui.py
index 321379eb8..4755ad813 100644
--- a/fsspec/gui.py
+++ b/fsspec/gui.py
@@ -119,7 +119,7 @@ def _signal(self, event):
         widget components.
         """
         if not self._ignoring_events:
-            wn = "-".join([event.obj.name, event.name])
+            wn = f"{event.obj.name}-{event.name}"
             if wn in self._map and self._map[wn] in self._sigs:
                 self._emit(self._map[wn], event.new)
 
diff --git a/fsspec/implementations/reference.py b/fsspec/implementations/reference.py
index 2df8b0e0d..c3f1e078e 100644
--- a/fsspec/implementations/reference.py
+++ b/fsspec/implementations/reference.py
@@ -160,9 +160,7 @@ def __getattr__(self, item):
 
     def setup(self):
         self._items = {}
-        self._items[".zmetadata"] = self.fs.cat_file(
-            "/".join([self.root, ".zmetadata"])
-        )
+        self._items[".zmetadata"] = self.fs.cat_file(f"{self.root}/.zmetadata")
         met = json.loads(self._items[".zmetadata"])
         self.record_size = met["record_size"]
         self.zmetadata = met["metadata"]
@@ -210,7 +208,7 @@ def create(root, storage_options=None, fs=None, record_size=10000, **kwargs):
         if fs.exists(root):
             fs.rm(root, recursive=True)
         fs.makedirs(root, exist_ok=True)
-        fs.pipe("/".join([root, ".zmetadata"]), json.dumps(met).encode())
+        fs.pipe(f"{root}/.zmetadata", json.dumps(met).encode())
         return LazyReferenceMapper(root, fs, **kwargs)
 
     @lru_cache()
diff --git a/fsspec/utils.py b/fsspec/utils.py
index 3c624be9c..b020cc8bd 100644
--- a/fsspec/utils.py
+++ b/fsspec/utils.py
@@ -74,7 +74,7 @@ def infer_storage_options(
     parsed_path = urlsplit(urlpath)
     protocol = parsed_path.scheme or "file"
     if parsed_path.fragment:
-        path = "#".join([parsed_path.path, parsed_path.fragment])
+        path = f"{parsed_path.path}#{parsed_path.fragment}"
     else:
         path = parsed_path.path
     if protocol == "file":
@@ -415,7 +415,7 @@ def other_paths(
             if exists:
                 cp = cp.rsplit("/", 1)[0]
             if not cp and all(not s.startswith("/") for s in paths):
-                path2 = ["/".join([path2, p]) for p in paths]
+                path2 = [f"{path2}/{p}" for p in paths]
             else:
                 path2 = [p.replace(cp, path2, 1) for p in paths]
     else:
diff --git a/pyproject.toml b/pyproject.toml
index ef707f50d..01a712039 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -162,6 +162,7 @@ select = [
     "E7",
     "E9",
     "F",
+    "FLY",
     "FURB",
     "I",
     "LOG",