如何在 python 中使用我自己的 class 中定义的变量正确打印句子

Question

So I created a class in python called Pizza, which takes 4 arguments...I want to be able to insert the arguments and then print it so that it comes out in a clean sentence. For example if I put this into the terminal---

from Pizza import Pizza
appetizer = Pizza("Pepperoni", 16, 10.50, 10)
print(appetizer)

I would want to get this result--- Your Pepperoni pizza has a diameter of 16 inches, a price of $10.5, and 10 slices per pie

Unfortunately, with my code I keep getting this when I print out the variable---

<Pizza.Pizza object at 0x7f17b762f650>

Anyone know why this is happening? My code is below

class Pizza:
    def __init__(self, name, diameter, price, slices):
        self.name = name
        self.diameter = diameter
        self.price = price
        self.slices = slices
    def myfunc(self):
        print("Your" +  self.name + "pizza has a diameter of" + self.diameter + "inches, a price of" + self.price + "and" + self.slices + "slices per pie")

Answer 1

Great question: It's possible to make the name of the object be a str function:

class Pizza:
    def __init__(self, name, diameter, price, slices):
        self.name = name
        self.diameter = diameter
        self.price = price
        self.slices = slices
    def __repr__(self):
        return "Your {} pizza has a diameter of {} inches, a price of {} and {} slices per pie".format(self.name,self.diameter,self.price,self.slices)


appetizer = Pizza("Pepperoni", 16, 10.50, 10)
print(appetizer)

Answer 2

try

from Pizza import Pizza
appetizer = Pizza("Pepperoni", 16, 10.50, 10).myfunc()
#you don't need to print appetizer because myfunc does it already

and also, change class Pizza to this

class Pizza:
    def __init__(self, name, diameter, price, slices):
        self.name = name
        self.diameter = diameter
        self.price = price
        self.slices = slices
    def myfunc(self):
        print("Your " +  self.name + " pizza has a diameter of " + str(self.diameter) + " inches, a price of " + str(self.price) + " and " + str(self.slices) + " slices per pie")

so it doesn't cause a "TypeError: can only concatenate str (not "int") to str" error

Answer 3

You're telling Python to print the Pizza object, so it happily complies:). Also in your myfunc() method you're adding strings to numbers (this will cause an error).

You should try this instead:

class Pizza:
    def __init__(self, name, diameter, price, slices):
        self.name = name
        self.diameter = diameter
        self.price = price
        self.slices = slices
    def myfunc(self):
        print("Your", self.name, "pizza has a diameter of", self.diameter, "inches, a price of", self.price, "and", self.slices, "slices per pie")

and

from Pizza import Pizza
appetizer = Pizza("Pepperoni", 16, 10.50, 10)
appetizer.myfunc()

output: Your Pepperoni pizza has a diameter of 16 inches, a price of 10.5 and 10 slices per pie