小白自学Python，仅做个人消息记录。
Exercise 1: Write a while loop that starts at the last character in thestring and works its way backwards to the first character in the string,printing each letter on a separate line, except backwards.
from operator import index
your_string = 'adsfgaeqgasdhergherhre'
index = -1
while index >= -(len(your_string)):
letter = your_string[index]
print(letter)
index = index - 1
Exercise 3: Encapsulate this code in a function named count, andgeneralize it so that it accepts the string and the letter as arguments.
def CountString(your_string, letter):
count = 0
for letter_you_need in your_string:
if letter_you_need == letter:
count += 1
print(count)
CountString('AppDataaaa2022pythonexe', 'e')
