Python一些小例子的代码

文本操作，实现边输入边输出

#实现边输入边输出  需要去Windows 找到该记事本文件，修改其内容并保存才可以真正的做到
import os
f_read = open(r"..\day6\四大喜事.txt",mode = "r",encoding="utf-8")
print(f_read.read())
while True:
    time_before = os.stat(r'..\day6\四大喜事.txt').st_mtime
    if os.stat(r'..\day6\四大喜事.txt').st_mtime != time_before:
        f_read = open(r"..\day6\四大喜事.txt", mode="r", encoding="utf-8")
        print(f_read.read())
    f_read.close()

冒泡排序：

爬一个小网站的内容

import  requests

def get_url():
    url = "http://www.xiaohuar.com/"

    def get():
        ret = requests.get(url)  #获取相应码
        def url_():
            text = ret.text    #获取源码文件
            return text
        return url_
    return get

text = get_url()()()
print(text)

二分查找

def find_second(data_list,val):
    '''
    :param data_list: 顺序储存结构
    :param val: 需要查找的值
    :return:  存在返回该值的索引，不存在返回None
    '''
    left = 0
    right = len(data_list) - 1
    while right >= left:
        middle = (right + left) // 2
        if val > data_list[middle]:
            left = middle +1
        elif val < data_list[middle]:
            right = middle -1
        else:
            return middle
    return

 

Python 的元组排序：

li = [(1,1,1),(1,0,1),(0,0,0),(1,1,0),(0,0,1)]
"""
F F F   3
F F T   5
T F T   2
T T F   4
T T T  1

"""
li.sort()
# print(sorted(li))  #结果：[(0, 0, 0), (0, 0, 1), (1, 0, 1), (1, 1, 0), (1, 1, 1)]
print(li)  #结果：[(0, 0, 0), (0, 0, 1), (1, 0, 1), (1, 1, 0), (1, 1, 1)]

 

接受实际报错信息

try:
    print(1/0)
except ZeroDivisionError:
    s = traceback.format_exc()  #实际报错信息
    s_index = s.index(':',1)
    print(type(s))
    print(s[s_index+1:].strip())

小帕爬虫读取页面全部信息

import  requests
# ret = requests.get("http://www.xiaohuar.com/")
# print(ret.text)
def get_url():
    url = "http://www.xiaohuar.com/"

    def get():
        ret = requests.get(url)
        def url_():
            text = ret.text
            return text
        return url_
    return get
text = get_url()()()
print(text)

模拟进度条

import sys
import time

def progress(percent,width=50):
    if percent >= 1:
        percent=1
    # show_str = ('%%-%ds' % width) % (int(width*percent)*'?')
    print('\r%s%d%%' %(int(width*percent)*'?', int(100*percent)), end='')

#=========应用==========
data_size=205000
recv_size=0
while recv_size < data_size:
    time.sleep(0.1) #模拟数据的传输延迟
    recv_size+=1024 #每次收1024

    percent=recv_size/data_size #接收的比例
    progress(percent,width=70) #进度条的宽度70

展示文件夹内容

#打开文件夹
import os
file_path = "d:\"
 
def readFile(file_path , n):     #n 控制循环深度 
    it = os.listdir(file_path)    #查看文件夹中的文件
    
    for em in it:                #遍历文件
        #if os.path.isdir(em):    #判断是否为文件夹
        if os.path.isdir(os.path.join(file_path, em))
            print('\t'*n,em)     #打印文件夹
            #readFile(em)        #此时找不到，因为只是文件名，找的是相对位置。   
            readFile(os.path.join(file_path, em ) , n+1)           #如果是，继续调用本方法
        else:
            print('\t'*n,em)     #打印文件
 
readFile(file_path , 0)