Hi, here's your problem today. This problem was recently asked by Amazon:
Given a string, return the first recurring letter that appears. If there are no recurring letters, return None.
Input: qwertty Output: t Input: qwerty Output: None
Here's some starter code:
def first_recurring_char(s): # Fill this in. print(first_recurring_char('qwertty')) # t print(first_recurring_char('qwerty')) # None