练习用的代码段

中文：

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

存为utf-8格式的文件：

# -*- coding: utf-8 -*-
import codecs;
f = codecs.open('d:/test111.txt', 'w', 'utf-8');
f.write('存为utf-8格式的文件..............')
f.close();

 保存文件：

#保存文件
string = 'ssssssss'
#string = input('please input string:')
with open('d:/test223.txt', 'a') as file:
    file.write(string)
file.close()

 输出多行文本：2015-12-31

print r'''"To be, or not to be": that is the question.
Whether it's nobler in the mind to suffer.'''
# 结果是两行文字

输入两个数字，排序：

#输入两个数字，排序
x = int(input('please input x:'))  
y = int(input('please input y:'))  
if x > y :  
    x, y = y, x 
print(x,y)

 循环：

#循环
for i in range(2,10):
    if i%2==0:
        print ("偶数",i)
    else:
        print ("奇数",i)

 int与string之间的转化：

int('12')       #10进制string --> int
int('ff', 16)   #16进制string --> int
str(18)         #int --> 10进制string
hex(18)         #int --> 16进制string

当前时间：

import time
now=time.strftime('%Y-%m-%d %H:%M:%S',time.localtime(int(time.time())-24*60*60))
print(now)

时间戳转换为指定日期：

# -*- coding: utf-8 -*-
#时间戳转换为指定格式日期:
import time
#timeStamp = 1381419600
timeStamp = int(time.time())     #当前时间戳
timeArray = time.localtime(timeStamp)   #本地时间
formatTime = time.strftime("%Y-%m-%d %H:%M:%S", timeArray)
print(formatTime)

import datetime
#获得当前时间
now = datetime.datetime.now()   #这是时间数组格式
formatTime = now.strftime("%Y-%m-%d %H:%M:%S")
print(formatTime)

将字符串的时间转为时间戳

#将字符串的时间转换为时间戳
import time
now = "2015-11-1 23:30:00"
timeArray = time.strptime(now, "%Y-%m-%d %H:%M:%S")
timeStamp = int(time.mktime(timeArray))
print(timeStamp)

#字符串格式更改： 如now = "2015-11-01 23:30:00",想改为 now = "2015年11月01日  23:40:00"
#方法:先转换为时间数组,然后转换为其他格式
import time
now = "2015-11-01 23:30:00"
timeArray = time.strptime(now,"%Y-%m-%d %H:%M:%S")
formatTime = time.strftime("%Y/%m/%d %H:%M:%S", timeArray)
print(formatTime)

计算3天以前：

#计算3天以前
import time
import datetime
threeDayAgo = (datetime.datetime.now() - datetime.timedelta(days = 3))
timeStamp = int(time.mktime(threeDayAgo.timetuple()))
formatTime = threeDayAgo.strftime("%Y-%m-%d %H:%M:%S")
print(formatTime)

扒取页面并保存：

#扒取页面并保存
import urllib.request as request
url = "http://www.163.com/"
doc = request.urlopen(url).read()
with open('d:/test.txt','wb') as file:
    file.write(doc)
    file.close()

存成utf-8文件：

# -*- coding: utf-8 -*-
import codecs
for i in range(2,5):
    iii=str(i)     #数字转字符串
    doc = ('数值是： '+iii)
    if i%2==0:
        doc += (" 偶数")
    else:
        doc += (" 奇数")
    f = codecs.open('d:/test'+iii+'.txt', 'w', 'utf-8');
    f.write(doc)
    f.close()

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