fix python (#54724)

test/ps/gpubox_run.sh

@@ -45,7 +45,7 @@ do
     cur_port=${PADDLE_PSERVER_PORT_ARRAY[$i]}
     echo "PADDLE WILL START PSERVER "$cur_port
     export PADDLE_PORT=${cur_port}
-    python3.7 -u $SC &> ./log/pserver.$i.log &
+    python -u $SC &> ./log/pserver.$i.log &
 done
 
 # run trainer
@@ -54,7 +54,7 @@ for((i=0;i<$PADDLE_TRAINERS;i++))
 do
     echo "PADDLE WILL START Trainer "$i
     export PADDLE_TRAINER_ID=$i
-    python3.7 -u $SC &> ./log/worker.$i.log
+    python -u $SC &> ./log/worker.$i.log
 done
 
 if [ $? -eq 0 ];then