python count unique characters in string of list code example

Example 1: find unique char in string python

In [1]: list(set('aaabcabccd'))
Out[1]: ['a', 'c', 'b', 'd']

Example 2: python count distinct letters

string = 'aabbcd'
unique = []
for char in string[::]:
    if char not in unique:
        unique.append(char)
print(len(unique))