Python栈与队列（十一）

Python栈与队列

一、栈

栈的特点：先进后出，后进先出；总结：先存的数据最后出栈，后存的数据最先出栈

# 模拟栈结构
stack = []

# 压栈(向栈里存数据)
stack.append("A")
print(f"stack = {stack}")       # stack = ['A']

stack.append("B")
print(f"stack = {stack}")       # stack = ['A', 'B']

stack.append("C")
print(f"stack = {stack}")       # stack = ['A', 'B', 'C']


# 出栈(在栈里取数据)
res1 = stack.pop()
print(f"res1 = {res1}")         # res1 = C

res2 = stack.pop()
print(f"res2 = {res2}")         # res2 = B

res3 = stack.pop()
print(f"res3 = {res3}")         # res3 = A

print(f"stack = {stack}")       # stack = []

栈模拟递归遍历目录(深度遍历)

import os
def getAllDirDE(path):
    # 创建空栈
    stack = []
    # 压栈
    stack.append(path)
    # 处理栈，当栈为空时结束循环
    while len(stack) != 0:
        # 从栈里取出数据
        dirPath = stack.pop()
        # 验证是否为绝对路径
        # print(dirPath)
        # 目录下所有文件
        dirList = os.listdir(dirPath)
        # 将这个file目录下的文件、目录打印出来
        # print(dirList)
        # for处理每一个文件，如果是普通文件就打印出来，如果是目录则将该目录的地址压栈
        for fileName in dirList:
            fileAbsPath = os.path.join(dirPath, fileName)
            if os.path.isdir(fileAbsPath):
                # 是目录就压栈
                print("目录：" + fileName)
                # 进队
                stack.append(fileAbsPath)
            else:
                # 打印普通文件
                print("文件：" + fileName)

getAllDirDE(r"D:\PyCharm\PyCharm 2018.3.7\file.py\文件处理\file")

二、队列

队列的特点：先进先出，后进后出；总结：先存的数据最先出列，后存的数据最后出列

# 模拟队列的结构
import collections      # 引导数据集合的模块


# deque() 创建队列
queue = collections.deque()
print(f"queue = {queue}", type(queue))         # queue = deque([]) <class 'collections.deque'>


# 进队(存数据)
queue.append("A")
print(f"queue = {queue}")       # queue = deque(['A'])

queue.append("B")
print(f"queue = {queue}")       # queue = deque(['A', 'B'])

queue.append("C")
print(f"queue = {queue}")       # queue = deque(['A', 'B', 'C'])


# 出队(取数据)
rts1 = queue.popleft()
print(f"rts1 = {rts1}")         # rts1 = A
print(f"queue = {queue}")       # queue = deque(['B', 'C'])

rts2 = queue.popleft()
print(f"rts2 = {rts2}")         # rts2 = B
print(f"queue = {queue}")       # queue = deque(['C'])

rts3 = queue.popleft()
print(f"rts3 = {rts3}")         # rts3 = C
print(f"queue = {queue}")       # queue = deque([])

队列模拟递归遍历目录(广度遍历)

import os
import collections

def getAllDirQU(path):
    queue = collections.deque()
    # 进队
    queue.append(path)

    while len(queue) != 0:
        # 出队数据
        dirPath = queue.popleft()
        # 找出所有的文件
        filesList = os.listdir(dirPath)

        for fileName in filesList:
            # 绝对路径
            fileAbsPath = os.path.join(dirPath, fileName)
            # 判断是否为目录，是目录就进队，不是目录则打印

            if os.path.isdir(fileAbsPath):
                print("目录：" + fileName)
                # 进队
                queue.append(fileAbsPath)
            else:
                print("文件：" + fileName)


getAllDirQU(r"D:\PyCharm\PyCharm 2018.3.7\file.py\文件处理\file")