今天做些能回顧所學知識點的小練習，類似的問題參考別人的代碼，修改成自己容易理解的模樣。

1、實現簡單的棧。put(item)實現數據item插入棧中；get()實現從棧中取一個數據。

# -*- coding: utf-8 -*-


class MyStack(object):
    '''MyStack
        自定義棧，操作有put(), get()
    '''
    def __init__(self):

        self.head = -1
        self.stack = []
    
    def put(self, item):

        self.head += 1
        self.stack.append(item)
        print('Put %s Success' % item)
    
    def get(self):

        if self.head < 0:
            return "Put Error: The Stack is Overflow!"
        else:
            self.head -= 1
            return self.stack.pop()
        
    def isEmpty(self):

        return self.item == []
        
        
if __name__ == "__main__":
    mystack = MyStack()
    mystack.put('a')
    mystack.put('b')
    print(mystack.get())
    mystack.put('c')
    print(mystack.get())
    print(mystack.get())
    print(mystack.get())

運行結果如下：

Put a Success
Put b Success
b
Put c Success
c
a
Put Error: The Stack is Overflow!

2、判斷指定網頁使用的編碼。

# -*- coding: utf-8 -*-
import sys
import requests
import chardet


def web_detect(url):
    
    #檢測網頁的編碼方式
    
    try:
        response = requests.get(url)
    except:
        print('error')
        return 0
    web= response.content
    response.close()
    codedetect = chardet.detect(web)["encoding"]
    print('%s\t<-\t%s' % (url, codedetect))
    return 1
    
if __name__ == '__main__':

    if len(sys.argv) == 1:
        print('usage:\n\tpython XX.py http://xxx.com')
    else:
        web_detect(sys.argv[1])

運行效果如下：

C:\>python webdetect.py http://blog.51cto.com/9473774
http://blog.51cto.com/9473774   <-      utf-8
C:\>python webdetect.py http://www.163.com
http://www.163.com      <-      GB2312

3、遍歷指定目錄下的所有文件，找出其中占用空間最大的前3個文件。

# -*- coding: utf-8 -*-
import sys
import os


def get_top_three(path):
    
    d = {}
    for root, dirs, files in os.walk(path):
        for file in files:
            fname = os.path.join(root, file)
            fsize = os.stat(fname).st_size
            d[fname] = fsize
    #print(d)
    f = sorted(zip(d.values(), d.keys()))
    for i in [-1, -2, -3]:
        for j in f[i]:
            print(j)
            
            
get_top_three('E:\\iso\\CentOS-6.8-x86_64-bin-DVD1')

運行結果如下：

146313216
E:\iso\CentOS-6.8-x86_64-bin-DVD1\images\install.img
45373440
E:\iso\CentOS-6.8-x86_64-bin-DVD1\images\efidisk.img
40688737
E:\iso\CentOS-6.8-x86_64-bin-DVD1\isolinux\initrd.img

《可愛的Python》讀書筆記（八）