s=input('input a string:\n')
letters=0
space=0
digit=0
others=0
for c in s:
    if c.isalpha():
        letters+=1
    elif c.isspace():
        space+=1
    elif c.isdigit():
        digit+=1
    else:
        others+=1
print('char=%d,space=%d,digit=%d,others=%d'%(letters,space,digit,others))

运行结果：

input a string:

gkjtrlkhgq  43678 ';m,2345gf erwhy

char=18,space=5,digit=9,others=3