from assignments import MaxSizeList  # assumes "class MaxSizeList"
                                     # is in a script called "assignments.py"

a = MaxSizeList(3)
b = MaxSizeList(1)

a.push("hey")
a.push("hi")
a.push("let's")
a.push("go")

b.push("hey")
b.push("hi")
b.push("let's")
b.push("go")

print(a.get_list())
print(b.get_list())
 Output
 # ['hi', "let's", 'go']
 # ['go']

class MaxSizeList(object):

ls = []

    def __init__(self,mx):
        self.val = mx


    def push(self,st):
        self.ls.append(st)



    def get_list(self):
        while len(self.ls) != self.val:
            self.ls.pop(0)
        return self.ls