tprofiler.utils.stack

A high-performance stack implementation using deque.

This module provides a Stack class that implements the Last-In-First-Out (LIFO) data structure using Python’s deque for optimal performance. The stack supports all standard stack operations with O(1) time complexity.

Stack

class tprofiler.utils.stack.Stack

A high-performance stack implementation using deque.

This class implements a Last-In-First-Out (LIFO) data structure using Python’s deque for better performance compared to list-based implementations. All basic stack operations (push, pop, peek) have O(1) time complexity.

Example:

>>> stack = Stack()
>>> stack.push(1)
>>> stack.push(2)
>>> stack.peek()
2
>>> stack.pop()
2
>>> stack.size
1

__bool__()

Support for boolean value judgment.

Returns:

True if the stack is not empty, False if empty.

Return type:

bool

Example:

>>> stack = Stack()
>>> bool(stack)
False
>>> stack.push(1)
>>> bool(stack)
True

__init__()

Initialize an empty stack.

Uses deque implementation for better performance with O(1) operations.

__len__()

Support for the len() function.

Returns:

The number of items in the stack.

Return type:

int

Example:

>>> stack = Stack()
>>> stack.push(1)
>>> stack.push(2)
>>> len(stack)
2

__str__()

Return a string representation of the stack.

Returns:

String representation showing the stack contents.

Return type:

str

Example:

>>> stack = Stack()
>>> stack.push(1)
>>> stack.push(2)
>>> str(stack)
'Stack([1, 2])'

clear()

Remove all items from the stack.

After calling this method, the stack will be empty.

Example:

>>> stack = Stack()
>>> stack.push(1)
>>> stack.push(2)
>>> stack.clear()
>>> stack.is_empty
True

property is_empty

Check if the stack is empty.

Returns:

True if the stack is empty, False otherwise.

Return type:

bool

Time complexity: O(1)

Example:

>>> stack = Stack()
>>> stack.is_empty
True
>>> stack.push(1)
>>> stack.is_empty
False

peek()

Return the top item from the stack without removing it.

Returns:

The top item from the stack.

Return type:

Any

Raises:

IndexError – If the stack is empty.

Time complexity: O(1)

Example:

>>> stack = Stack()
>>> stack.push(42)
>>> stack.peek()
42
>>> stack.size
1

pop()

Remove and return the top item from the stack.

Returns:

The top item from the stack.

Return type:

Any

Raises:

IndexError – If the stack is empty.

Time complexity: O(1)

Example:

>>> stack = Stack()
>>> stack.push(42)
>>> stack.pop()
42

push(item)

Push an item onto the top of the stack.

Parameters:

item (Any) – The item to push onto the stack.

Time complexity: O(1)

Example:

>>> stack = Stack()
>>> stack.push(42)
>>> stack.size
1

property size

Get the number of items in the stack.

Returns:

The number of items in the stack.

Return type:

int

Time complexity: O(1)

Example:

>>> stack = Stack()
>>> stack.size
0
>>> stack.push(1)
>>> stack.push(2)
>>> stack.size
2