如何在 flask python 中同時返回 1 個裝飾器下的不同結果

Question

I m currently deploying my LSTM model in flask python, I would like to ask how do I return my new CSV file together with my plot graph under one @app.route into a page, hence I need some advice and tips regarding this issues.

執行代碼時出現此錯誤>> TypeError: The view function did not return a valid response. The function either returned None or ended without a return statement. TypeError: The view function did not return a valid response. The function either returned None or ended without a return statement.

應用程序.py

@app.route('/transform', methods=["POST"])
def transform_view():
 if request.method == 'POST':
    f = request.files['data_file']
    if not f:
        return "No file"    

    
    stream = io.StringIO(f.stream.read().decode("UTF8"), newline=None)
    csv_input = csv.reader(stream)
    stream.seek(0)
    result = stream.read()
    df = pd.read_csv(StringIO(result), usecols=[1])
    
    #extract month value
    df2 = pd.read_csv(StringIO(result))
    matrix2 = df2[df2.columns[0]].to_numpy()
    list1 = matrix2.tolist()
     
    # load the model from disk
    model = load_model('model.h5')
    dataset = df.values
    dataset = dataset.astype('float32')
    scaler = MinMaxScaler(feature_range=(0, 1))
    dataset = scaler.fit_transform(dataset)
    look_back = 1
    dataset_look = create_dataset(dataset, look_back)
    dataset_look = np.reshape(dataset_look, (dataset_look.shape[0], 1, dataset_look.shape[1]))
    predict = model.predict(dataset_look)
    transform = scaler.inverse_transform(predict)

    X_FUTURE = 12
    transform = np.array([])
    last = dataset[-1]
    for i in range(X_FUTURE):
        curr_prediction = model.predict(np.array([last]).reshape(1, look_back, 1))
        last = np.concatenate([last[1:], curr_prediction.reshape(-1)])
        transform = np.concatenate([transform, curr_prediction[0]])
  
    transform = scaler.inverse_transform([transform])[0]

    dicts = []
    curr_date = pd.to_datetime(list1[-1])
    for i in range(X_FUTURE):
        curr_date = curr_date +  relativedelta(months=+1)
        dicts.append({'Predictions': transform[i], "Month": curr_date})


    new_data = pd.DataFrame(dicts).set_index("Month")
    ##df_predict = pd.DataFrame(transform, columns=["predicted value"])

def index(chartID = 'chart_ID', chart_type = 'line', chart_height = 550):
    chart = {"renderTo": chartID, "type": chart_type, "height": chart_height}
    series = [{"name": 'Month', "data": [1,2,3]}]
    title = {"text": 'Time Series Sales Predicting'}
    xAxis = {"categories": ['xAxis Data1', 'xAxis Data2', 'xAxis Data3']}
    yAxis = {"title": {"text": 'Sales'}}
     

    response = make_response(new_data.to_csv(index = True, encoding='utf8'))
    response.headers["Content-Disposition"] = "attachment; filename=result.csv"
    return response
    return render_template('graph.html', chartID=chartID, chart=chart, series=series, title=title, xAxis=xAxis, yAxis=yAxis) 

Answer 1

從您的錯誤消息中，您的transform_view() function 不返回任何內容。 考慮在它的底部添加一個return語句，就像你對index()所做的那樣

@app.route('/transform', methods=["POST"])
def transform_view():
    if request.method == 'POST':
        # ...
    return # <your_response>

維護你的index() function

def index(chartID = 'chart_ID', chart_type = 'line', chart_height = 550):
    # ...
    return render_template(# ...)