Python- Help with try: input() except ValueError: Loop code to start of sequence

[Aldi]

Good Evening,
I have been learning python for about a week now and decided to try and write a financial calculator program (however painstaking due to my complete lack of knowledge. I am having trouble with user input and try:. I would like to restart the program back to user input when the user inputs a str or float rather than an int. I can get the program to print "please use a real number" if they input something other than an int, but I don't know how to get it to restart.

I know my code is probably dreadfully inefficient, and I am still working the calculation at the end for compound interest. (Help appreciated there too!)

Respectfully yours,
Aldi

1 2 3 4 5 6 7 8 9 10 11 12 13 14

try:     age = int(input("What is your age?"))     retirement_age = int(input("At what age would you like to retire?")) except ValueError:     print("Please use a whole number") years_to_save = int(retirement_age-age) print(f'You have {years_to_save} years to save.') try:     mnth_svng_no_intrest = int(input("How much money will you save per month?")) except ValueError:     print("Use a real number, rounded to the tenth") life_svng_no_intrest = int(years_to_save*mnth_svng_no_intrest)*12 print(f'That is great! If you do NOTHING but save that money, you will have ${life_svng_no_intrest} at retirement.') interst_at_ten = (mnth_svng_no_intrest(1*.1)**1)

[ka06059]

this should give you the idea on how to loop a code when error occured

1 2 3 4 5 6

while True:     try:         variable = int(input())         break     except:         print("try again")

[Larz60+]

Actually, the except clause should be qualified.
if you don't know what type of exception, you can find out as follows:
following will intentionally create an exception:

1 2 3 4 5 6 7 8 9 10 11

>>> def get_numbase(): ...     numbase = 0 ...     try: ...         numbase = int(input('Enter numbase: ')) ...         return numbase ...     except: ...         print("Unexpected error:", sys.exc_info()[0]) ... >>> get_numbase() Enter numbase: how about this Unexpected error: <class 'ValueError'>

So this will show what type of exception is being thrown.

You can then correct your code as follows (yo can remove the import sys):

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

>>> def get_numbase(): ...     numbase = 0 ...     while True: ...         try: ...             numbase = int(input('Enter number base: ')) ...             return numbase ...         except ValueError: ...             print('Please enter numeric number base') ... >>> get_numbase() Enter number base: How about this Please enter numeric number base Enter number base: 10 10 >>>

Now, if some exception other than ValueError occurs, you will still get a traceback, but
Value Error will be properly captured and delt with