我试图从我的数据表中的一行返回一个值，并收到以下错误：
TypeError：“NoneType”对象不可下标（键“GCWR”）
这是错误中引用的代码片段...
"""
This function gets the GCWR of the truck from the 'truck_specifications' data table
Parameters: brand, model, year, engine, drive, axle
Returns: gcwr
"""
def get_gcwr(brand, model, year, engine, drive, axle):
gcwr_row = app_tables.truck_specifications.get(Brand=brand, Model=model, Year=year, Engine_Type=engine, Drive_Type=drive, Axle_Ratio=axle)
gcwr = gcwr_row['GCWR']
return gcwr
一些细节：
- 变量“gcwr”应该根据上面显示的参数从数据表中的特定行返回一个数字
- 这以前有效，但是当我开始向表中添加更多数据时，它现在给了我上面显示的错误
- 我已经根据参数手动查看了数据表，有一行符合条件，应该返回一个值
- 数据表中列的数据类型为“数字”
这是调用上述函数的代码片段......
"""
This function gets the truck specifications based on the users input
Parameters: none
Returns: value (allowable trailer GVWR)
"""
@anvil.server.callable
def get_truck_specifications():
# Get data from 'truck_inputs' data table
brand = get_brand()
model = get_model()
year = get_year()
engine = get_engine()
drive = get_drive()
axle = get_axle()
payload = int(get_payload())
passengers = int(get_passengers())
cargo = int(get_cargo())
hitch = int(get_hitch())
# Get data from 'truck_specifications' data table
gcwr = int(get_gcwr(brand, model, year, engine, drive, axle))
gvwr_truck = int(get_gvwr_truck(brand, model, year, engine, drive, axle))
base_weight = int(get_base_weight(gvwr_truck, payload))
gvw = base_weight + passengers + cargo + hitch
value = gcwr - gvw
return value
这是显示数据表示例的屏幕截图...
