[Python] Python TypeError when adding ord(c) + num in Caesar cipher implementation on Coderbyte

TypeError: unsupported operand type(s) for +: 'int' and 'str' in Caesar Cipher Implementation


I'm working on a Caesar cipher problem on Coderbyte for a fintech SWE position and encountering a TypeError that I can't resolve.

Problem


Getting TypeError: unsupported operand type(s) for +: 'int' and 'str' on line 8 where I'm trying to add ord(c) + num.

Code


def StringChallenge(strParam, num):
# code goes here
results = ""

for c in strParam:
if c.isalpha():
shifted_ord = ord(c) + num # ERROR ON THIS LINE
if "A" <= c <= "Z":
if shifted_ord > ord("Z"):
shifted_ord = shifted_ord - 26
elif "a" <= c <= "z":
if shifted_ord > ord("z"):
shifted_ord = shifted_ord - 26
results += chr(shifted_ord)
else:
results += c

challengeToken = "ngJ92ipqb70"
results += challengeToken

updated = ""
count = 1
for i in results:
if count == 4:
updated += "_"
count = 1
else:
updated += i
count += 1

return updated

# keep this function call here
print StringChallenge("Hello", 4)
print StringChallenge(raw_input())

Error Message


Traceback (most recent call last):
File "/tmp/422136455/main.py", line 41, in <module>
print StringChallenge("Argument goes here...", "Argument goes here...")
File "/tmp/422136455/main.py", line 8, in StringChallenge
shifted_ord = ord(c) + num
TypeError: unsupported operand type(s) for +: 'int' and 'str'

What I've Verified

• strParam is confirmed to be a string type
• num is confirmed to be an integer type
• ord(c) returns an integer
• The error occurs specifically on the addition operation

Question


Since ord(c) returns an int and num is an int, the addition ord(c) + num should work. What could be causing this TypeError?

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