[Tutor] Beginner problem: name 'convertToFahrenheit' is not defined

[Alan Gauld]

"Joseph Bae" <joeturf at gmail.com> wrote

> temp = input("Enter A Number : ")
> convertTo = raw_input("Convert To (F)ahrenheit or (C)elsius? : ")
>
> if convertTo == "F":
>    convertedTemp = convertToFahrenheit(temp)
>    print "%d Celsius = %d Fahrenheit" % (temp, convertedTemp)
> else:
>    convertedTemp = convertToCelsius(temp)
>    print "%d Fahrenheit = %d Celsius" % (temp, convertedTemp)
>
> def convertToFahrenheit(t):
>    tF = (9.0/5.0) * (t + 32)
>    return tF
>
> def convertToCelsius(t):
>    tC = (9.0/5.0) * (t - 32)
>    return tC
>
>          convertedTemp = convertToFahrenheit(temp)
> NameError: name 'convertToFahrenheit' is not defined
>
> This is most likely a very simple error, but can someone please 
> clarify for
> me why it's behaving this way?

Others have explained that you need to execute the function
definitions before Python sees the name. You can do this in
two ways depending on taste.
1) As suggested move your main code below the function definitions.
2) move your main code into a function - traditionally called main()
    then call main as the last line of your code.

The second method has two advantages:
1) It maintains the top-down design style if thats your preferred 
style
2) It makes it much easier to make the file into a reusable module.

It has two minor disadvantages:

1) The extra function call (main() ) slows things down by a tiny 
amount
2) the extra indentation level of being inside a function reduces the 
page
    width slightly

HTH,

-- 
Alan Gauld
Author of the Learn to Program web site
http://www.freenetpages.co.uk/hp/alan.gauld