def pretty_iban(iban):
 return ' '.join([iban[i:(i + 4)] for i in range(0, len(iban), 4)])

def pretty_iban ( iban ) : return ' ' . join ( [ iban [ i : ( i + 4 ) ] for i in range ( 0 , len ( iban ) , 4 ) ] )
return iban in groups of four characters separated by a single space .