CODEWITHSUNDEEP
pythontry-except
New Learner
New Learner

Reputation: 3

python try and except not giving expected values

Here is my python program

def try_ec(argument):
    try:
        int(argument)
    except:
        argument = input("Please enter a valid value: ")
a = []
score = 0
first = input("First Number: ")
try_ec(first)
first = int(first)
second = input("Second Number: ")
try_ec(second)
second = int(second)

Error

I am trying to get an integer from the user and i am using try and except if the user enters a string by mistake. However my code is giving this error. How do I make the code correct?

Upvotes: 0

Views: 170

Answers (3)

Sohaib
Sohaib

Reputation: 594

you might use recursion call method to convert it into Int.

   def try_ec(argument):
        try:
            return int(argument)
        except:
            inpt = input("Please enter a valid value: ")
            try_ec(inpt)


    a = []
    score = 0
    first = input("First Number: ")
    first = try_ec(first)
    second = input("Second Number: ")
    second = try_ec(second)

Upvotes: 0

The Fool
The Fool

Reputation: 20430

That is because you mutate a locale variable. First's value never changes.

Consider the following example 

a = 5

def mut(arg):
  arg = 6

mut(a)
print(a) // 5

This is because arg is ia local copy of the argument that was passed in, it lives only in that functions scope.

And here is how we could do it,

a = 5

def mut(arg):
  arg = 6
  return arg


a = mut(a)
print(a) // 6

By returning the new computed value and assigned it to our initial variable.

Upvotes: 1

Yusuf Berki YAZICIOGLU
Yusuf Berki YAZICIOGLU

Reputation: 128

You must use while loop to check the process until it is correct.

For example:

def take_int_input(text):
    while True:
        argument = input(text)
        try:
            return int(argument)
        except:
            print("Please enter a valid value!")




first = take_int_input("First Number: ")
second = take_int_input("Second Number: ")

Upvotes: 0

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