Python Pygorithm用法及代碼示例

Pygorithm module 是一個純粹用 Python 編寫的 Python 模塊，僅用於教育目的。隻需導入所需的算法即可獲得代碼、時間複雜度等等。這是開始學習 Python 編程和理解概念的好方法。 Pygorithm模塊還可以幫助學習Python語言中所有主要算法的實現。

要安裝 Pygorithm 模塊：

pip3 install pygorithm

例子：

# import the required data structure 
from pygorithm.data_structures import stack 
  
  
# create a stack with default stack size 10 
myStack = stack.Stack() 
  
# push elements into the stack 
myStack.push(2) 
myStack.push(5) 
myStack.push(9) 
myStack.push(10) 
  
# print the contents of stack 
print(myStack) 
  
# pop elements from stack 
myStack.pop() 
print(myStack) 
  
# peek element in stack 
print(myStack.peek()) 
  
# size of stack 
print(myStack.size()) 

輸出：

2 5 9 10
2 5 9
9
3

要查看模塊中的所有可用函數，隻需鍵入help()以模塊名稱作為參數。

# Help on package pygorithm.data_structures 
help(data_structures) 

輸出：

NAME
    pygorithm.data_structures - Collection of data structure examples

PACKAGE CONTENTS
    graph
    heap
    linked_list
    quadtree
    queue
    stack
    tree
    trie

DATA
    __all__ = ['graph', 'heap', 'linked_list', 'queue', 'stack', 'tree', '...

使用get_code()獲取任何data_structures的代碼。

# to get code for BinarySearchTree 
BStree = tree.BinarySearchTree.get_code() 
  
print(BStree) 

輸出：

class BinarySearchTree(object):
   
    def __init__(self):
        self.root = None

    def insert(self, data):
        """
        inserts a node in the tree
        """
        if self.root:
            return self.root.insert(data)
        else:
            self.root = BSTNode(data)
            return True

    def delete(self, data):
        """
        deletes the node with the specified data from the tree
        """
        if self.root is not None:
            return self.root.delete(data)

    def find(self, data):
        if self.root:
            return self.root.find(data)
        else:
            return False

    def preorder(self):
        """
        finding the preorder of the tree
        """
        if self.root is not None:
            return self.root.preorder(self.root)

    def inorder(self):
        """
        finding the inorder of the tree
        """
        if self.root is not None:
            return self.root.inorder(self.root)

    def postorder(self):
        """
        finding the postorder of the tree
        """
        if self.root is not None:
            return self.root.postorder(self.root)
    
    @staticmethod
    def get_code():
        """
        returns the code of the current class
        """
        return inspect.getsource(BinarySearchTree)

要了解以下腳本的複雜性：

# create a stack with default stack size 10 
Bsort = sorting.bubble_sort.time_complexities() 

輸出：

Best Case: O(n), Average Case: O(n ^ 2), Worst Case: O(n ^ 2).

For Improved Bubble Sort:
Best Case: O(n); Average Case: O(n * (n - 1) / 4); Worst Case: O(n ^ 2)

快速鏈接到 Pygorithm 源代碼