1 class Cpf:
   2     def __init__( self ):
   3         """ 
   4         Class to interact with CPF numbers
   5         """
   6         pass
   7 
   8     def format( self, cpf ):
   9         """ 
  10         Method that formats a brazilian CPF
  11         
  12         Tests:
  13         >>> print Cpf().format('91289037736')
  14         912.890.377-36
  15         """
  16         return "%s.%s.%s-%s" % ( cpf[0:3], cpf[3:6], cpf[6:9], cpf[9:11] )
  17 
  18     def validate( self, cpf ):
  19         """ 
  20         Method to validate a brazilian CPF number 
  21         Based on Pedro Werneck source avaiable at
  22         www.PythonBrasil.com.br
  23         
  24         Tests:
  25         >>> print Cpf().validate('91289037736')
  26         True
  27         >>> print Cpf().validate('91289037731')
  28         False
  29         """
  30         cpf_invalidos = [11*str(i) for i in range(10)]
  31         if cpf in cpf_invalidos:
  32             return False
  33        
  34         if not cpf.isdigit():
  35             """ Verifica se o CPF contem pontos e hifens """
  36             cpf = cpf.replace( ".", "" )
  37             cpf = cpf.replace( "-", "" )
  38 
  39         if len( cpf ) < 11:
  40             """ Verifica se o CPF tem 11 digitos """
  41             return False
  42             
  43         if len( cpf ) > 11:
  44             """ CPF tem que ter 11 digitos """
  45             return False
  46             
  47         selfcpf = [int( x ) for x in cpf]
  48         
  49         cpf = selfcpf[:9]
  50         
  51         while len( cpf ) < 11:
  52         
  53             r =  sum( [( len( cpf )+1-i )*v for i, v in [( x, cpf[x] ) for x in range( len( cpf ) )]] ) % 11
  54         
  55             if r > 1:
  56                 f = 11 - r
  57             else:
  58                 f = 0
  59             cpf.append( f )
  60         
  61         
  62         return bool( cpf == selfcpf )
  63 
  64 # test
  65 #import doctest ; doctest.testmod()