[Tutor] ValueError

[Johnson Tran]

Thanks for the replies..so I added the "try" block but it still does not seem to be outputting my default error message:

def Conversion():
    try:
        
        print "This program converts the first value from inches to centimeters and second value centimeters to inches."
        print "(1 inch = 2.54 centimeters)"
        inches = input("Enter length in inches: ")
        centimeters = 2.54 * float(inches)
        print "That is", centimeters, "centimeters."
        centimeters = input("Enter length in centimeters: ")
        inch = float(centimeters) / 2.54
        print "That is", inch, "inches."

    except ValueError:
         print "Invalid digit, please try again." 
Conversion()

Error message:

Traceback (most recent call last):
  File "/Users/JT/Desktop/hw#2.py", line 16, in <module>
    Conversion()
  File "/Users/JT/Desktop/hw#2.py", line 9, in Conversion
    centimeters = input("Enter length in centimeters: ")
  File "<string>", line 1, in <module>
NameError: name 'fs' is not defined


On May 3, 2011, at 4:00 AM, Corey Richardson wrote:

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> On 05/03/2011 06:30 AM, Johnson Tran wrote:
>> Hi All, 
>> 
>> i am trying to create a program module with two functions (conversion inches to centimeters then centimeter to inches, I have my program working although I am trying to adda Value Error function to my program but cannot seem to it to work:
>> 
>> 
>> def Conversion():
>>    print "This program converts the first value from inches to centimeters and second value centimeters to inches."
>>    print "(1 inch = 2.54 centimeters)"
>>    inches = input("Enter length in inches: ")
>>    centimeters = 2.54 * inches
>>    print "That is", centimeters, "centimeters."
>> 
>>    centimeters = input("Enter length in centimeters: ")
>>    inch = centimeters / 2.54
>>    print "That is", inch, "inches."
>> 
>>    except ValueError:
>>        print "Invalid digit, please try again."
>> 
>> Conversion()
>> 
>> 
>> 
>> Any advice would be great, thanks!
>> 
>> JT
> 
> Well, you need a 'try' block before that except. Example:
> 
> try:
>    foo = int("blargh")
> except ValueError:
>    pass
> 
> It looks like you're forgetting an important operation on the inches
> variable, as well as centimeters later on.
> 
> Take a look at
> http://docs.python.org/library/stdtypes.html#typesnumeric
> 
> For future questions, it's best to include what your program /is/ doing
> that you think it shouldn't be, as well as any errors (tracebacks, copy
> the whole thing!) you get.
> 
> - -- 
> Corey Richardson
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