Joseph Bae wrote:
Thanks for the help!
I have managed to get a good temperature converter program working! I am
working on beefing it up a bit with some exception handling and an "and-or
trick". The error handling works okay but I am having problems using and-or.
Here's my updated code:
def main():
true = 1
while true:
try:
temp = int(raw_input("Enter A Number : "))
break
except ValueError:
print "Invalid Input"
while true:
convertTo = raw_input("Convert To (F)ahrenheit or (C)elsius? : ")
if not convertTo == "F" and not convertTo == "C":
this might be easier to read as:
if convertTo != "F" and convertTo != "C":
or even:
if convertTo not in ("F", "C"):
print "Invalid Input"
* else:
convertTo == "C" and convertToCelsius(temp) or
convertToFahrenheit(temp)
I'd caution you against using and/or like this as a control flow
pattern. It can be very confusing compared to this:
if convertTo == "C":
convertToCelsius(temp)
else:
convertToFahrenheit(temp)
Note that the and/or pattern hides the bug you're facing. What you're
really doing with the and/or pattern is this:
if convertTo == "C":
if not convertToCelsuis(temp):
convertToFahrenheit(temp)
else:
convertToFahrenheit(temp)
So what you had will call convertToCelsuis(temp) AND if that didn't
return a true value, will ALSO call convertToFahrenheit(temp).
Since convertToCelsius() doesn't return a value at all, that's exactly
what happened.
break
*
def convertToCelsius(t):
tC = (9.0/5.0) * (t - 32)
print "%d Fahrenheit = %d Celsius" % (t, tC)
def convertToFahrenheit(t):
tF = (9.0/5.0) * (t + 32)
print "%d Celsius = %d Fahrenheit" % (t, tF)
That's not the correct calculation.
C = (F - 32) / 1.8
F = (C * 1.8) + 32
if __name__=="__main__":
main()
Sample Output (as of right now):
Enter A Number : 50
Convert to (F)ahrenheit or (C)elsius? C
50 Fahrenheit = 32 Celsius
32 Celsius = 147 Fahrenheit <-- shouldn't show up and 147 is too high ...
This only happens when I tell it to convert to C, if I say F it works
normally. I've debugged it with pdb.set_trace() many times but can't figure
out what's wrong. Help is much appreciated =)
Thanks,
Joe
On Thu, Aug 14, 2008 at 10:50 PM, Alan Gauld <[EMAIL PROTECTED]>wrote:
"Joseph Bae" <[EMAIL PROTECTED]> 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
_______________________________________________
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------------------------------------------------------------------------
_______________________________________________
Tutor maillist - Tutor@python.org
http://mail.python.org/mailman/listinfo/tutor
_______________________________________________
Tutor maillist - Tutor@python.org
http://mail.python.org/mailman/listinfo/tutor
