python里面如何输入数字

while True:

    ten=input('Enter a number:')

    if type(eval(ten))==type(int):

　　      break

while True:

    ten=input("x:")

    try:

        x=eval(ten)

        if type(x)==int:

            break

    except:

            pass

x:asf

x:344

while True:

    ten=None

    try:

        ten=int(input("x:"))

    except:

        pass

    if type(ten)==int:

        break

while True:

    ten=raw_input("Enter a number:")

    if ten.isdigit():

        break

    ten=int(ten)  #或者是ten=eval(ten)