stack.py -- An object-oriented, first principles implementation of a stack data structure, written in Python.

stack.py

class Stack:
    def __init__(self):
        self.stack = []
        self.stacklen = int(input(print("How long should the stack be?")))
                       
    def push(self):
        if len(self.stack) == self.stacklen:
            self.full()
        else:
            self.stack.append(int(input("Enter a value to append.\n")))
        
    def pop(self):
        if len(self.stack) == 0:
            self.empty()
        else:
            self.stack.pop()
        
    def peek(self):
        return self.stack[0]
    
    def full(self):
        if len(self.stack) == self.stacklen:
            return "Full."
        else:
            return "Not full."
    
    def empty(self):
        if len(stack) == 0:
            return "Empty."
        else:
            return "Not empty."
    
    def showme(self):
        return self.stack