Forgive me if any of my vocabulary is wrong, I am just starting to learn python.

I made a file for an assignment regarding cards. I think that it creates a class object? with its initiator method? I also included a specific method because we were supposed to tailor it to a file provided to us that called the method.

class Card:
    def __init__(self,suit,number):
        self.suit = suit
        self.number = number

    def get_display_string(self):
        if (self.suit == 1):
            self.suit = "Hearts"
        if (self.suit == 2):
            self.suit = "Diamonds"
        if (self.suit == 3):
            self.suit = "Clubs"
        if (self.suit == 4):
            self.suit = "Spades"
        if (self.number == 1):
            self.number = "Ace"
        if (self.number == 11):
            self.number = "Jack"
        if (self.number == 12):
            self.number = "Queen"
        if (self.number == 13):
            self.number = "King"
        return "{} of {}".format(self.number, self.suit)

I ran it a bunch and to my knowledge there was no mistakes in regards to getting the desired output. I got full credit as well, but the teacher comments stated I should be using elif instead of just if for comparing items in the same sequence. Is there a reason for this? What problems could arise? Did I just get lucky that this somehow worked?