Python 实现简单的命名合法性检查

#!/usr/bin/env python

def identifierChecker():

import string

alphas = string.ascii_letters + '_'
nums = string.digits
alphanums = alphas + nums
print 'Welcome to the Identifier Checker v1.0'
print 'Testees must be at least 2 chars long.'
myInput = raw_input('Identifier to test? ')

if len(myInput) > 1:

if myInput[0] not in alphas:
print '''invalid: first symbol must be alphabetic'''
else:
for otherChar in myInput [1:]:

if otherChar not in alphanums:
print '''invalid: remaining symbols must be alphanumeric'''
break
else:
print "Okay as an identifier"

In [8]: identifierChecker()
Welcome to the Identifier Checker v1.0
Testees must be at least 2 chars long.
Identifier to test? count4rer
Okay as an identifier

In [9]: identifierChecker()
Welcome to the Identifier Checker v1.0
Testees must be at least 2 chars long.
Identifier to test? 3d_effects
invalid: first symbol must be alphabetic

In [11]: identifierChecker()
Welcome to the Identifier Checker v1.0
Testees must be at least 2 chars long.
Identifier to test? 1

In [12]: