题解 | #字符个数统计#
字符个数统计
http://www.nowcoder.com/practice/eb94f6a5b2ba49c6ac72d40b5ce95f50
# 字符转ascii：ord
# ascii转字符：chr
char_set = set()
s = str(input())
for c in s:
ascii = ord(c)
if 0<=ascii<=127 and c!='\n':
if c not in char_set:
char_set.add(c)
print(len(char_set))