python – Why can't I pass a parameter to the class?

Question:

I'm trying to pass the "ink" parameter to the "Pen" class but I can't. I've tried using boolean expressions instead of index, but still with 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, "The ink ran out" appears, and "The pen is fine" should appear, because the parameter I set is "50".

Answer:

It lacks some logic in its code, besides having a certain error.

Firstly, you are not getting tinta as a parameter, and this is not even necessary since the value is already saved in the object. You are taking self as a parameter (which is the object itself). So instead of trying to directly access tinta , you must 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 loop to find out if the ink level is in a certain range, you just need to use the logical comparators < (less than) and > (greater than).

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

I made an adaptation in your code and now it is 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()