while/try/except decimal TypeError not working

I thought I could finally get some use out of the while/try/except loop, but I am encountering a problem. My task is to have the computer request numbers from a user until '0' is entered. After this, the numbers entered will be added. My problem is that the Except part isn't catching non-numeric entries. If a non-numeric entry is entered, I get a regular error message that stops the program. Here is what happens when I enter 3 numbers and the 4th entry is 'm':

on win32
Type "copyright", "credits" or "license()" for more information.
>>>
RESTART: C:/Users/Username/Documents/CISPROG1/Homework 5/Homework5.1.SumGenerator.py
Enter 1st element (or type '0' to finish).
1
Enter 2nd element (or type '0' to finish).
2
Enter 3rd element (or type '0' to finish).
3
Enter 4th element (or type '0' to finish).
m
Traceback (most recent call last):
File "C:/Users/Username/Documents/CISPROG1/Homework 5/Homework5.1.SumGenerator.py", line 24, in <module>
+ "%s element (or type '0' to finish). n" % suffix()))
decimal.InvalidOperation: [<class 'decimal.ConversionSyntax'>]
>>>


I thought this would be a "TypeError" but that isn't catching it. In fact, not even "Exception" error type catches it. How do I catch non-numeric input? I think the problem has something to do with how Python handles non-numeric input for a Decimal type.

Here is my program:

from decimal import *

#start:
lInputSequence =
i = 1

def suffix():
if i%10 == 1 and i != 11:
return "st"
elif i%10 == 2 and i != 12:
return "nd"
elif i%10 == 3 and i != 13:
return "rd"
else:
return "th"

decInputElement = 1
while True:
decInputElement = Decimal(input("Enter " + str(i)
+ "%s element (or type '0' to finish). n" % suffix()))
try:
if decInputElement == 0:
break
else:
lInputSequence.append(decInputElement)
i = i+1
except TypeError:
print("Please enter a number.")
print(lInputSequence)
print("The sum of these %s elements is %s" % (len(lInputSequence),sum(lInputSequence)))
#end


1 Answer
1

So, it looks like the problem is two-fold:

Solution:

This doesn't get to the root of what kind of error is coming up but it catches any input errors.

from decimal import *

#start:
lInputSequence =
i = 1

def suffix():
if i%10 == 1 and i != 11:
return "st"
elif i%10 == 2 and i != 12:
return "nd"
elif i%10 == 3 and i != 13:
return "rd"
else:
return "th"

decInputElement = 1
while True:
try:
decInputElement = Decimal(input("Enter " + str(i)
+ "%s element (or type '0' to finish). n" % suffix()))
if decInputElement == 0:
break
else:
lInputSequence.append(decInputElement)
i = i+1
except Exception:
print("Please enter a number.")
print(lInputSequence)
print("The sum of these %s elements is %s" % (len(lInputSequence),sum(lInputSequence)))
#end


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