Remove duplicates in a string

Write a function remove_duplicates that takes a string and returns a new string with duplicate characters removed, keeping the first occurrence of each character.

Premium

def remove_duplicates(str):

   # complete function here...

 
 
print(remove_duplicates('banana')) # expected output: 'ban'
 
print(remove_duplicates('vegetable')) # expected output: 'vegtabl'
 
print(remove_duplicates('difficulty')) # expected output: 'difculty'

Python

Setting up Python environment...

Output