I am trying to code a class that makes use of Push and Pop from a stack (with single linked list). I am not sure how to write the push and pop functions. I really need a开发者_高级运维 simple example written in Python with the following functions.
Push
Pop
ifEmpty
From the docs that Dyno Fu linked to:
The list methods make it very easy to use a list as a stack, where the last element added is the first element retrieved (“last-in, first-out”). To add an item to the top of the stack, use
append()
. To retrieve an item from the top of the stack, usepop()
without an explicit index. For example:
>>> stack = [3, 4, 5]
>>> stack.append(6)
>>> stack.append(7)
>>> stack
[3, 4, 5, 6, 7]
>>> stack.pop()
7
>>> stack
[3, 4, 5, 6]
>>> stack.pop()
6
>>> stack.pop()
5
>>> stack
[3, 4]
And finally, to check if a list is empty:
>>> my_list = []
>>> not my_list
True
And here is the simplest stack class:
class stack(list):
def push(self,item):
self.append(item)
def isEmpty(self):
return not self
>>> a = stack()
>>> a.push(1)
>> a.isEmpty()
False
>>> a.pop()
1
>>> a.isEmpty()
True
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