fix string format

app.py

@@ -110,7 +110,7 @@ def run(hf_token, service, game, functionality, nlp_command):
             )
             calling_end = beijing()
             timecost = calling_end.timestamp() - calling_start.timestamp()
-            print(f"calling ai ends at {calling_end}, costs %.2fs" % timecost)
+            print(f"calling ai ends at {calling_end}, costs {timecost:.2f}s")
             outp = json.loads(res)
             # add proxy version info to the output
             outp["proxy-version"] = proxy_version
@@ -121,7 +121,7 @@ def run(hf_token, service, game, functionality, nlp_command):
             app_util.call_logger(outp, identity, token)
             calling_end = beijing()
             timecost = calling_end.timestamp() - calling_start.timestamp()
-            print(f"calling logger ends at {calling_end}, costs %.2fs" % timecost)
+            print(f"calling logger ends at {calling_end}, costs {timecost:.2f}s")
         except Exception as e:
             return (
                 f"{type(e)}, {str(e)}. \nyou may want to make "
@@ -130,8 +130,8 @@ def run(hf_token, service, game, functionality, nlp_command):
     service_end = beijing()
     timecost = service_end.timestamp() - service_start.timestamp()
     print(
-        f">>>>>>>>>>>>>>> service ends at {service_end}, costs %.2f <<<<<<<<<<<<<<<"
-        % timecost
+        f">>>>>>>>>>>>>>> service ends at {service_end}, "
+        + f"costs {timecost:.2f} <<<<<<<<<<<<<<<"
     )
     return json.dumps(outp, indent=4)