#!/usr/bin/env python

class Console:     
    # valid entries only for numbers
    @staticmethod    
    def inputNumber(msg ,value):
        while True:
            var = input(msg + " " + value + " : ")
            try:
                var = int(var)
                return var
            except ValueError:    
                print("invalid")                             
    #valid entries only for letters     
    @staticmethod
    def inputString(msg,value):     
        while True:
            var = input(msg + " " + value + " : ")            
            if Console.__charactersNotNumber(var) == False:                
                return var
            else:
                print("invalid")                
    #valid entries only for letters    
    @staticmethod           
    def inputDecimal(msg, value):
        while True:
            var = input(msg + " "+ value + " : ")
            try:
                var = float(var)
                return var
            except ValueError:
                print("invalid")
    #valid entries only for alphabetical      
    @staticmethod
    def inputAlpha(msg, value):
        while True:
            var = input(msg + " " + value)
            if var.isalpha():
                return var
            else:
                print("invalid")
    @staticmethod           
    def inputDigital(msg, value):
        while True:
            var = input(msg + " " + value)
            if var.isdigit():
                return var
            else:
                print("invalid")
    @staticmethod             
    def inputSpace(msg, value):         
        while True:
            var = input(msg + " " + value)
            if var.isspace():
                return var
            else:
                print("invalid")               
                 
    @staticmethod          
    def __charactersNotNumber(cadena):
        try:
            float(cadena)
            return True
        except (TypeError, ValueError):
            return False

#num = Console.inputNumber("ingrese", "un numero ")           
        
    