关于python判断参数是否是合法标识符介绍

import string

def is_valid_identifier(param):
 alphas = string.letters + '_'
 nums = string.digits

 if len(param) > 1:
 if param[0] not in alphas:
 print 'invalid:first symbol must be alphabetic'
 else:
 for otherChar in param[1:]:
 if otherChar not in alphas + nums:
 print 'invalid:reminding symbols must be alphanumeric'
 break
 else:
 print 'okay, %s is an valid identifier'%param


is_valid_identifier('class')