I am having a fastapi to do predictions and returing the output as a response but i have implemented input checking where if the user gives unsupported input it returns a Invalid smile but the problem here is the response dictionary is not replaced.

when i do the prediction i got this response

{"result":{"interaction_map":[[15.0,5.0,14.0,15.0,15.0],[19.0,7.0,20.0,19.0,19.0],[13.0,6.0,18.0,13.0,13.0],[15.0,5.0,14.0,15.0,15.0],[15.0,5.0,14.0,15.0,15.0]],"predictions":-3.405024290084839}}

But when i give a wrong input i got this response

{"result":{"interaction_map":[[15.0,5.0,14.0,15.0,15.0],[19.0,7.0,20.0,19.0,19.0],[13.0,6.0,18.0,13.0,13.0],[15.0,5.0,14.0,15.0,15.0],[15.0,5.0,14.0,15.0,15.0]],"predictions":"invalid SMILES"}}

But i am expecting this response

{"predictions":"invalid SMILES"}

This is the code i am using

response = {}
async def predictions(solute, solvent):
    m = Chem.MolFromSmiles(solute,sanitize=False)
    n = Chem.MolFromSmiles(solvent,sanitize=False)
    if (m == None or n == None):
      response['predictions']= 'invalid SMILES'
      print('invalid SMILES')
    else:
      mol = Chem.MolFromSmiles(solute)
      mol = Chem.AddHs(mol)
      solute = Chem.MolToSmiles(mol)
      solute_graph = get_graph_from_smile(solute)
      mol = Chem.MolFromSmiles(solvent)
      mol = Chem.AddHs(mol)
      solvent = Chem.MolToSmiles(mol)
      solvent_graph = get_graph_from_smile(solvent)
      delta_g, interaction_map =  model([solute_graph.to(device), solvent_graph.to(device)])
      interaction_map_one = torch.trunc(interaction_map)
      response["interaction_map"] = (interaction_map_one.detach().numpy()).tolist()
      response["predictions"] = delta_g.item()

@app.get('/predict_solubility')
async def post():
    return {'result': response}

@app.get('/predict')
async def predict(background_tasks: BackgroundTasks,solute,solvent):
    background_tasks.add_task(predictions,solute,solvent)
    return {'success'}