判断类型：数字、字母、空格等

str_1 = "123"

str_2 = "Abc"

str_3 = "123Abc"

 

#用isdigit函数判断是否数字

print(str_1.isdigit())

Ture

print(str_2.isdigit())

False

print(str_3.isdigit())

False

 

#用isalpha判断是否字母

print(str_1.isalpha())   

False

print(str_2.isalpha())

Ture   

print(str_3.isalpha())   

False

 

#isalnum判断是否数字和字母的组合

print(str_1.isalnum())   

Ture

print(str_2.isalnum())

Ture

print(str_1.isalnum())   

Ture

注意：如果字符串中含有除了字母或者数字之外的字符，比如空格，也会返回False。

 

 

import string

s = raw_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)