MNT: Work around pandas value set on slice warning

funpack/loadtables.py

@@ -807,14 +807,12 @@ def mergeTableFiles(
             # non-na values in later files take
             # precedence.
             for c in [c[:-2] for c in merged.columns if c.endswith('_x')]:
-                bcolname        = c + '_x'
-                tcolname        = c + '_y'
-                bcol            = merged[bcolname]
-                tcol            = merged[tcolname]
-                notna           = tcol.notna()
-                bcol.loc[notna] = tcol[notna]
-                merged[c]       = bcol
-                merged          = merged.drop(columns=[bcolname, tcolname])
+                bname                = c + '_x'
+                tname                = c + '_y'
+                merged[c]            = merged[bname]
+                notna                = merged[tname].notna()
+                merged.loc[notna, c] = merged.loc[notna, tname]
+                merged               = merged.drop(columns=[bname, tname])
             base = merged
 
     # no base, and no files