a bit simpler

stand/api.py

@@ -20,18 +20,14 @@ def append(beamline: Beamline, pgroup: PGroup, run: int, row: dict[str, Any]):
     index = pd.Timestamp(run) # adb supports update only for timeseries indexes
     index = pd.Index([index], name="run")
 
-    run_exists = not adb.get(beamline).read(
-        pgroup,
-        date_range=index,
-        columns=[]
-    ).data.index.empty
+    lib = adb.get(beamline)
 
+    run_exists = not lib.read(pgroup, date_range=index, columns=[]).data.index.empty
     if run_exists:
         raise HTTPException(409, f"run {run} exists already in {beamline}/{pgroup}")
 
     df = pd.DataFrame(row, index=index)
-
-    adb.get(beamline).append(pgroup, df)
+    lib.append(pgroup, df)
 
     row = {"run": run, **row} # setdefault would not force run to be the first column