Avoid ValueError outside a while loop?-CodePudding

In the second line, I am trying to make it not crash if a string is entered but can't find a way to use an exception or something similar. In the while loop it works normally as the exception deals with this case.

number = 0 #this to be removed
number = (float(input('pick a number'))) #I want to make this not crash if a string is entered.
while number not in [100, 200, 3232]:
    try:
        print('wrong number ')
        number = (float(input('pick a number;'))) #Here it does not crash if a string is entered which is fine
    except ValueError:
        print("retry")

CodePudding user response：

while followed by a variable condition often ends up with bugs/repeating code => bad maintenability.

Use a while True condition to avoid repeating your code, then break out the loop when it's valid.

while True:
    try:
        number = (float(input('pick a number;')))
        if number in [100, 200, 3232]:
           break
        print("wrong number")
    except ValueError:
        print("illegal number, retry")

as a side note, for those valid values, float should probably be int as any floating point value would be rejected anyway unless the decimal part is .0

CodePudding user response：

Maybe create a function to take input:

def get_input():
    while True:
        a = input("Pick a number: ")
        try:
            return float(a)
        except:
            pass