def reverse(lst):
right = len(lst) - 1
left = 0
while left < right:
if not lst[left].isalpha():
left += 1
elif not lst[right].isalpha():
right -= 1
else:
lst[left], lst[right] = lst[right], lst[left]
left += 1
right -= 1
return lst
lst = ['a', '#', 'b', '$', '%', 'c', '&', '*', '(', 'd', 'e', 'f', '!']
lst = reverse(lst)
print(lst)
'''
run:
['f', '#', 'e', '$', '%', 'd', '&', '*', '(', 'c', 'b', 'a', '!']
'''