Exercise 07-03:
Write a program that reads two strings and generates a third one with the characters that appear in only one string.
1st string: CTA
2nd string: ABC
3rd string: BT
The order of the characters in the third string is not important.
Answer:
##############################################################################
# Python From Scratch
# Author: Nilo Ney Coutinho Menezes
# Editora Novatec (c) 2010-2025 - LogiKraft 2025
# Site: https://pythonfromscratch.com
# ISBN: 978-85-7522-949-1 (Paperback), 978-85-7522-950-7 (hardcover), 978-85-7522-951-4 (ebook)
#
# File: chapter 07/exercise-07-03.py.py
##############################################################################
first = input("Enter the first string: ")
second = input("Enter the second string: ")
third = ""
# For each letter in the first string
for letter in first:
# Check if the letter does not appear in the second string
# and also if it's not already listed in the third
if letter not in second and letter not in third:
third += letter
# For each letter in the second string
for letter in second:
# Besides not being in the first string,
# check if it's not already in the third (avoid repetitions)
if letter not in first and letter not in third:
third += letter
if third == "":
print("No uncommon characters found.")
else:
print(f"Uncommon characters: {third}")