输入一行字符，分别统计出其中英文字母、空格、数字和其他字

letters,space,digit,other=0,0,0,0
s=input("请输入一行字符：")
for i in range(len(s)):
    if (s[i]>='a' and s[i]<='z') or (s[i]>='A' and s[i]<='Z'):
        letters+=1
    elif s[i]==' ':
        space+=1
    elif s[i]>='0' and s[i]<='9':
        digit+=1
    else:
        other+=1
print("字母数：%d\n空格数：%d\n数字数：%d\n其他字符数：%d\n"%(letters,space,digit,other))
 

或

p=input('请输入一行字符:')
a,b,c,d=0,0,0,0
for i in p:
    if((i<='Z' and i>='A') or (i<='z' and i>='a')):
        a+=1
    elif (i==' '):
        b+=1
    elif(i>='0' and i<='9'):
        c+=1
    else:
        d+=1
print ('英文字母的个数为：'+str(a))
print ('空格的个数为：'+str(b))
print ('数字的个数为：'+str(c))
print ('其他字符的个数为：'+str(d))

或

letter,space,digit,other=0,0,0,0
s = input('input a string:')
for c in s:
    if c.isalpha():
        letter +=1
    elif c.isspace():
        space +=1
    elif c.isdigit():
        digit +=1
    else:
        other +=1
print("字母数：%d\n空格数：%d\n数字数：%d\n其他字符数：%d\n"%(letter,space,digit,other))