get-uniq-codepoints-small-input-or-small-alphabet.py

#!/usr/bin/env python3
"""O(n**2) solution for small input or alphabet"""
text = input('Введите строку: ') # Ой ёж ежовый
uniq = ''
for char in text:
    if char not in uniq:
        uniq += char
print(uniq)
# -> Ой ёжовый