Why can’t I pass a parameter to the class?

Question

I’m trying to pass the parameter "ink" to the class "Pen" but I can’t. I’ve tried using boolean expressions instead of index, but still no result. Could someone give me a help?

class Caneta():

    açao = 'escrever'

    def __init__(self, tinta):
        self.tinta = tinta

    def NivelTinta(tinta):
        rng = range(0,100)

        for tinta in rng:
            if tinta in rng[5:100]:
                print('A caneta está boa')
                break
            elif tinta in rng[1:4]:
                print('A caneta está falhando')
                break
            else:
                print('A tinta acabou')
                break

CanetaAzul = Caneta(50)

CanetaAzul.NivelTinta()

Every time I run the code appears "The ink is gone", and should appear "The pen is good", because the parameter I put is "50".

Answer 1

It lacks a little logic in its code, in addition to having a certain error.

First of all, you’re not getting tinta as parameter, and this is not even necessary once the value is already saved in the object. You are receiving self as parameter (which is the object itself). So instead of trying to access directly tinta, you need to access the property (or attribute) tinta that is within the parameter (also called tinta, in this case - I changed the name to self just to avoid confusion).

Second, this loop is completely unnecessary. You don’t need to make a loop to find out if the ink level is in a certain range, just use the logical comparators < (less than) and > (greater than).

Another important thing, even if the loop be necessary, the instruction break with the code "jump out of the loop", this means that the conditions will be assessed only once and after that the loop is stopped.

I made an adaptation to your code and now it’s functional.

class Caneta():

    acao = 'escrever'

    def __init__(self, tinta):
        self.tinta = tinta

    def NivelTinta(self):
        print(self.tinta)

        if(1 <= self.tinta <= 5):
            print('A caneta esta falhando')
        elif(5 < self.tinta <= 100):
            print('A caneta esta boa')
        else:
            print('A tinta acabou')

CanetaAzul = Caneta(50)
CanetaAzul.NivelTinta()