Coverting an input string into an interger - python-3.x

Question

#This program calculates the average of integer entered
#Once the use press "S".
#"S" is the sentinel
COUNT= 0
SUM= 0
INT=1
Sentinel = "S"
print('Enter test scores as integers, or enter S to get average.')
INT=input('Enter integer: ') # input received as a string to allow for the entry of "S"
#Continue processing as long as the user
#does not enter S
while INT!= Sentinel:
INT=input('Enter integer: ')
I=int(INT) #attempting to format the input(INT) as an integer
COUNT= + 1
SUM = COUNT + I
if INT == Sentinel:
AVRG= SUM/(COUNT-1)
I keep getting this error message :
Traceback (most recent call last):
File "C:\Users\joshu\Documents\COP100 Python\practice examples\program4-13.py", line 16, in
I=int(INT)
ValueError: invalid literal for int() with base 10: 'S'

Answer 1

Your code is assuming that the user will always enter a numeric value.
This line will accept any data entered by the user. It could be numeric or non-numeric.
INT=input('Enter integer: ') # input received as a string to allow for the entry of "S"
Before you convert the data into integer, check if the value is numeric. If it is not, then you may want to send an error message back to the user.
I=int(INT) #attempting to format the input(INT) as an integer
You can do that by doing:
if INT.isnumeric():
I = int(INT)
else:
print ('not a numeric value')
I am assuming that users will enter only integers. The above code will work only for integers. If you want to check for floats, then use a try: except statement.
Also, your computation of SUM to get the average is incorrect. You shouldn't add COUNT to SUM. You should only add I to SUM while incrementing COUNT.
Also don't try to use variable names as sum, int (even if it is uppercase).
Here's a working code for you to try.
count = 0
total = 0
Sentinel = "S"
#Continue processing as long as the user does not enter S
while True:
test_score = input('Enter test score as integer or enter S to get average: ')
# input received as a string to allow for the entry of "S"
if test_score.isnumeric():
score = int(test_score) #attempting to format the input(INT) as an integer
count += 1
total += score
elif test_score.upper() == Sentinel:
break
else:
print ('Not an integer or S. Please re-enter the value')
if count > 0:
print (total, count)
average_score = total/count
print ('average score is : ', average_score)
else:
print ('No valid entries were made. Average score is N/A')