How to get the required output in python?

Question

Define class Temperature, whose initializer method accepts temperature in fahrenheit unit. Define a descriptor class Celsius with two methods namely get,which returns temperature in celsius units.set,which allows to change temperature to new value in celsius unit.

Input : 1)t1=Temperature(32)   2)t1.celsius=0
Output: 1)32,0.0               2)32.0,0.0

1st input refers to fahrenheit value and 2nd input refers to celsius value

I have tried to write the code but without success:

class Celsius:
    def __init__(self, temp = 0):
        self.temp = temp
    def to_fahrenheit(self):
        return (self.temp * 1.8) + 32
    def __get__(self):
        return(self.temp)
    def __set__(self,temp):
        self.temp=temp
    desc=property(__get__,__set__)
class Temperature:
   def __init__(self,temp=0):
       self.fahrenheit=temp
       self.celsius=(((self.fahrenheit-32)*5)/9)
       c=Celsius()
       c.desc=self.celsius
       self.fahrenheit=c.to_fahrenheit()

    The output I got is 1)32.0 , 0.0     2)32.0 , 0

Please let me if any modification required in the code.

Answer 1

It looks like you're trying to solve a problem that's trying to teach you about descriptors. Take a look at https://docs.python.org/3.7/howto/descriptor.html for more details.

But all that's needed for the problem you're writing a solution for:

class Celsius:
    def __get__(self, obj, objtype):
        return ((obj.fahrenheit - 32) * 5) / 9

    def __set__(self, obj, celcius):
        obj.fahrenheit = ((celcius * 9) / 5) + 32


class Temperature:
    celcius = Celsius()

    def __init__(self, fahrenheit=0):
        self.fahrenheit = fahrenheit

Note a few important differences with your code:

• Celcius is instantiated and directly assigned to celcius on the class, instead of to an attribute on the Temperature instance, as in your case.
• The descriptor performs the conversion in both directions, without complication on the Temperature class.
• Most of the extra code on your implementation didn't do anything; as a general rule, if you add code to try to solve a problem, don't keep it around if it doesn't solve the problem. Less is more in programming.

Answer 2

This is working for me

class Celsius:

def __get__(self, instance, owner):

    return 5 * (instance.fahrenheit - 32) / 9



def __set__(self, instance, value):

    instance.fahrenheit = 32 + 9 * value / 5

   

class Temperature:

celsius = Celsius()



def __init__(self, initial_f):

    self.fahrenheit = initial_f

    

t = Temperature(32)

print(t.celsius)

print(t.fahrenheit)