correctly calculate group and move group to in-memory calculation

prep-parquet-for-s5cmd/fpart-db.py

@@ -34,16 +34,12 @@ def main():
     ddf = dd.read_parquet(input_parquet)
     ddf = ddf.loc[ddf['path'].str.startswith(filter)].sort_values('path')
 
-
-    ddf = ddf.loc[~ddf['mode'].str.startswith('d')].reset_index(drop=True)
-
-
-    ddf['group'] = np.floor(ddf.index/split_count).astype(int) + 1
+    ddf = ddf.loc[~ddf['mode'].str.startswith('d')]
 
     ddf['cmd'] = ddf['path'].map(lambda x: create_sync_cmd(x, filter=filter, dest=dest), meta=str)
-
-
-    df = ddf[['group','cmd']].compute()
+    
+    df = ddf[['cmd']].compute().reset_index(drop=True)
+    df['group'] = np.floor(df.index/split_count).astype(int) + 1
 
 
     os.makedirs(part_dir,exist_ok=True)