Try-Except 块 - 我这样做是否正确？

Question

我们正在学习异常处理。我这样做正确吗？ ValueError 是用于捕获正在键入的字符串而不是数字的正确异常吗？我尝试使用 TypeError，但它没有捕捉到异常。

此外，是否有更有效的方法来捕获我的四个输入中的每个异常？这里的最佳做法是什么？

#Ask user for ranges. String inputs are not accepted and caught as exceptions. While loop repeats asking user for input until a float number is input.
while True:
    try:
        rangeLower = float(input("Enter your Lower range: "))
    except ValueError:
        print("You must enter a number!")
    else:
        #Break the while-loop
        break
while True:
    try:
        rangeHigher = float(input("Enter your Higher range: "))
    except ValueError:
        print("You must enter a number!")
    else:
        #Break the while-loop
        break
#Ask user for numbers. String inputs are not accepted and caught as exceptions. While loop repeats asking user for input until a float number is input.
while True:
    try:
        num1 = float(input("Enter your First number: "))
    except ValueError:
        print("You must enter a number!")
    else:
        #Break the while-loop
        break
while True:
    try:
        num2 = float(input("Enter your Second number: "))
    except ValueError:
        print("You must enter a number!")
    else:
        #Break the while-loop
        break

Answer 1

这里你体验的就是所谓的，WET代码Write Everything Twice，我们尝试写DRY代码，即Don't重复自己。

在你的情况下，你应该做的是创建一个名为 float_input 的函数，使用你的 try except 块并为每个变量赋值调用它。

def float_input(msg):
    while True:
        try:
            return float(input(msg))
        except ValueError:
            pass


range_lower = float_input('Enter your lower range: ')
...

Try-Except 块 - 我这样做是否正确？

Try-Except block - Did I do this correctly?

python

exception

try-except