CODEWITHSUNDEEP
pythondata-structures
user12150264
user12150264

Reputation:

Is it better to implement a data structure with a class or with built-in structures?

I am learning about data structures and had a question. In textbook I am reading they show an implementation of a stack like this :

class Stack:
     def __init__(self):
         self.items = []

     def isEmpty(self):
         return self.items == []

     def push(self, item):
         self.items.append(item)

     def pop(self):
         return self.items.pop()

     def peek(self):
         return self.items[len(self.items)-1]

     def size(self):
         return len(self.items)

I do not get the need for creating a whole new class ? Why cant they just create a stack as such :

myStack = []

>>> myStack.append('a')
>>> myStack.append('b')
>>> myStack.append('c')

>>> myStack
['a', 'b', 'c']

>>> myStack.pop()
'c'
>>> myStack.pop()
'b'
>>> myStack.pop()
'a'

Is it faster or more versatile? I want to understand the difference so I am able to make decisions about how to implement one when needed.

Thank you!

Upvotes: 0

Views: 334

Answers (2)

ForceBru
ForceBru

Reputation: 44838

A built-in data structure (like list) will almost always be faster than anything written in Python. And this implementation of Stack uses a list as the stack anyway, so it just adds additional overhead then.

If a data structure is not built into Python and is not provided by the standard library, then you'll have to create a class. You can create a class if the built-in data structure doesn't provide the methods you need (like peek) as well.

Upvotes: 0

Alex Hall
Alex Hall

Reputation: 36033

This is just a basic example to give you a feel for how to implement your own data structure. A list is already good enough to use as a stack, but for more complicated data structures there won't be anything built in that works so well.

Upvotes: 1

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