相关疑难解决方法(0)

我正在编写一个必须接受用户输入的程序.

#note: Python 2.7 users should use `raw_input`, the equivalent of 3.X's `input`
age = int(input("Please enter your age: "))
if age >= 18: 
    print("You are able to vote in the United States!")
else:
    print("You are not able to vote in the United States.")

如果用户输入合理数据,这将按预期工作.

C:\Python\Projects> canyouvote.py
Please enter your age: 23
You are able to vote in the United States!

但如果他们犯了错误,那就崩溃了:

C:\Python\Projects> canyouvote.py
Please enter your age: dickety six
Traceback (most recent call last):
  File "canyouvote.py", line 1, in …

这里的Python新手,尝试将测验输入限制为仅限1,2或3.
如果键入文本,程序崩溃(因为文本输入无法识别)
这是对我所拥有的改编:欢迎任何帮助.

choice = input("Enter Choice 1,2 or 3:")
if choice == 1:
    print "Your Choice is 1"
elif choice == 2:
    print "Your Choice is 2"  
elif choice == 3:
    print "Your Choice is 3"
elif choice > 3 or choice < 1:
    print "Invalid Option, you needed to type a 1, 2 or 3...."

我试图允许用户输入我的程序,但是当他们输入一个字符串我的程序失败.这是一个更大的计划,但试图纠正这个问题,我到目前为止:

data = raw_input('Enter a number: ')
number = eval(data)
if type(number) != int:
     print"I am afraid",number,"is not a number"
elif type(number) == int:
    if data > 0:
        print "The",number,"is a good number"
    else:
        print "Please enter a positive integer"

当用户输入字符串时,它返回:

number = eval(data)
  File "<string>", line 1, in <module>
NameError: name 'hel' is not defined

非常感激任何的帮助.