'How to display a message when a string is input instead of an int?

here is a beginner. I'm doing an exercise-code which tells you if you are poor, rich or neither rich nor poor depending on the value typed by the user. I would like to print an error message in case the user is typing a non int variable.... Of course it gives an error as I put int before the input function...here the code:

money=int(input())

if money <10000:
   print('you are poor '+name)
elif money >= 10000 and money<100000:
   print('you are neither poor nor rich '+ name)
elif money >=100000:
   print('you are rich ')

Could you show me how to do it?

pythonpython-3.xif-statementtypespythondjangopostgresqlmigration


Solution 1:[1]

You can catch the exception which happens when you try to convert to integer:

try:
    money=int(input())
except ValueError:
    print("That is not an integer!")

Solution 2:[2]

Thanks a lot everybody for the answers! They were all good but the following code I guess was the best:

while True: # Infinite loop
    try:
        money = int(input()) # Try to convert the input into a number
        break                # Break out of the infinite loop if the conversion is successful
    except ValueError:       # Do this instead if the try block causes a ValueError
        print("Sorry, that is not an integer. Please try again.")

if money < 10000:
    print('you are poor ' + name)
elif money >= 10000 and money < 100000:
    print('you are neither poor nor rich ' + name)
elif money >= 100000:
    print('you are rich ' + name)

with the while loop the code stop to move on when the input is not a int. In the other cases, the try and except work but when the input is not an int , the code print the error message wanted but continue to run the if statement by generating a error message

Solution 3:[3]

One option is to use a try catch, that way you can handle the error.

Something like this:

try:
    money=int(input())

    if money <10000:
        print('you are poor '+name)
    elif money >= 10000 and money<100000:
        print('you are neither poor nor rich '+ name)
    elif money >=100000:
        print('you are rich ')

except:
    print("Input is not a valid number")

Solution 4:[4]

Use exceptions to handle the input of such values

try:
    money=int(input())

    if money <10000:
       print('you are poor '+ name)
    elif money >= 10000 and money<100000:
       print('you are neither poor nor rich '+ name)
    elif money >=100000:
       print('you are rich ')
except:
    print("error")

Solution 5:[5]

try to get an integer for input() and send to money;

try:
money=int(input())

then, you will need an except, in order to handle error;

except:
print('You should enter an integer!')

Solution 6:[6]

you need to you the else condition and for

ValueError

you need a try,except block

try:
    money=int(input())
    
    if money <10000:
       print('you are poor '+name)
    elif money >= 10000 and money<100000:
       print('you are neither poor nor rich '+ name)
    elif money >=100000:
       print('you are rich ')
    else:
       print('wrong value')
except ValueError:
    print("not an integer")

Solution 7:[7]

As you have already use int function before input it will only accept integer value.

In case user input a string value, use the try except to print the error messege. This will prevent your program from getting crashed.

try:
   money=int(input())

   if money <10000:
       print('you are poor '+name)
   elif money >= 10000 and money<100000:
       print('you are neither poor nor rich '+ name)
   elif money >=100000:
       print('you are rich ')

Except:
   print("Please enter valid data")

Please take care of indentation.

Golden Tip-- Instead of int use float as it will accept the decimal value too

Solution 8:[8]

It may be a bit risky but it has worked for me in the past. I suggest creating a copy of your project in another folder and trying this safely away from the original project. Also if you are using a postgresql database then just switch to a dummy database although it shouldn't make a difference but just to be on the safer side.

Inside of your migrations folder, inside the app folder, try deleting the all the files inside of pycache EXCEPT init.cpython-39.pyc and 0001_initial.cpython-39.pyc and inside of the migrations folder delete all files EXCEPT init.py and 0001_initial.py.

IMPORTANT: Delete from the pycache INSIDE of migrations NOT the one outside of it.

Solution 9:[9]

The approach below has often helped me out, if its a production database its good to backup and also your migrations folder before getting started.

  • Start by deleting your current applications migrations folder
  • temporarily add a field to your models.
  • Makemigrations then migrate
  • Delete the temporarily added field from your model
  • Makemigrations and migrate

Sources

This article follows the attribution requirements of Stack Overflow and is licensed under CC BY-SA 3.0.

Source: Stack Overflow

Solution Source
Solution 1 zvone
Solution 2 Giacomo Bonvini
Solution 3
Solution 4 NewGCorp
Solution 5 Melisa Özen
Solution 6
Solution 7 Nimantha
Solution 8 lakimapturn
Solution 9

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