用户输入列表python

Question

我正在尝试获取output_values的总和，这给了我一个追溯错误

output_values = []
while True:
    user_input = input('Please type in your test grades, and follow your input by typing in "done"')
    if user_input == 'done':
        print('All done, here is your average')
        break
    ### here you will insert in the traceback error to prevent your code from crashing due to invalid input
    try:
        val_input = float(user_input)
        if val_input:
            output_values.append(user_input)
    except ValueError:
        print('You have typed in an invalid input, please type in your grade as a numerical digit')
        continue
print(output_values)
summation = sum(output_values)

Answer 1

您将user_input从str转换为float，并将返回值分配给val_input，但是当您附加到output_values时，您将其{ 1}}，而不是user_input，有效地放弃了转化。

val_input

只需使用以下方法修复它：

    val_input = float(user_input)
    if val_input:
        output_values.append(user_input)