Python: Temperature converter only works f to c, not other way around?

Asked Mar 23 '15 at 15:42

Active Mar 24 '15 at 17:33

Viewed 35 times

The temp converter should do exactly as assumed, f to c, or c to f.

It works from f to c (except negatives don't show up?), but it doesn't work when converting from c to f.

print "Temperature Converter"
temp = 0

def user_temp():
  temp = raw_input("Enter a temperature: ")
  return float(temp)


def convert():
   conv = raw_input("Convert to (F)ahrenheit or (C)elsius? ")
   if conv.lower() == "f":
    new_temp = (9 / 5) * (temp + 32)
    print new_temp
    user_temp()
  elif conv.lower() == "c":
    new_temp = (5 / 9) * (temp - (32))
    print new_temp
    user_temp()

user_temp()
convert()

The user_temp() within the if/elif is simply so I could continually test numbers, not to annoy users with an infinite loop.

edited Mar 24 '15 at 17:33

JasonMArcher

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asked Mar 23 '15 at 15:42

Charles Watson

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3

You never assigned the `user_temp()` return value anywhere. Neither conversion works. `temp` in the `user_temp()` function is a *local*. – Martijn Pieters Mar 23 '15 at 15:44
2

Keep also in mind that you should divide by `9.` instead of `9`. – Mathias711 Mar 23 '15 at 15:44
1

F = C × 9/5 + 32, note that multiplication has the higher precedence, so what you want is (temp*9/5) + 32, not (9/5)*(temp+32). – Shashank Mar 23 '15 at 15:45
2

watch your indent on the `elif` – logic Mar 23 '15 at 15:45
Either way, `5 / 9` is `0`, because you are using integer division. See the duplicate target. – Martijn Pieters Mar 23 '15 at 15:46
There's no reason to call user_temp again after your print statements. – Shashank Mar 23 '15 at 15:48
I call user_temp again after the print statement only so that it would rerun and I could keep testing numbers. vs "python foo.py" in order to start it repeatedly. – Charles Watson Mar 23 '15 at 15:56

Python: Temperature converter only works f to c, not other way around?

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