【程序17】输入一行字符，分别统计出其中英文字母、空格、数字和其它字符的个数

s = input('input a string:
')
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))