Repeating charachters

Question

How can a function that takes one argument and only accept characters between a-z and remove any duplicates in the string be put in code form in Python.
It should return a tuple with two variables
1. A new string with uniquely sorted characters.
2. The total number of duplicates dropped.
e.g.,
rem_duplicate ('aabbac') => ('abc', 3)
rem_duplicate ('a') => ('a', 0)
rem_duplicate ('theleash')=>('aehlst', 2)

Answer 1

Already corrected the mistake

Answer 2

these examples are wrong

Answer 3

use a list to count the numbers of each alphabet

Answer 4

This doesn't check for a-z range:

https://code.sololearn.com/c4ehY66V1upT/?ref=app

Answer 5

https://code.sololearn.com/cMCzwF9TMzoE