Python 有权重的随机选择, Weighted Random Choice
import random def windex(lst):
'''an attempt to make a random.choose() function that makes weighted choices
accepts a list of tuples with the item and probability as a pair'''
wtotal = sum([x[1] for x in lst])
n = random.uniform(0, wtotal)
for item, weight in lst:
if n < weight:
break
n = n - weight
return item
相关文档:
Python的os模块,包含了普遍的操作系统功能,这里主要学习与路径相关的函数:
os.listdir(dirname):列出dirname下的目录和文件
os.getcwd():获得当前工作目录
os.curdir:返回当前目录('.')
os.chdir(dirname):改变工作目录到dirname
os.path.isdir(name):判断name是不是一个目录,name不是目录就返回false
......
#
-*- encoding: gb2312 -*-
import
os, sys, string
import
MySQLdb
#
连接数据库
try
:
conn
=
MySQLdb.connect(host
=
'
localhost
'
,user
=
'
root
'
,passwd
=
'
xxxx
'
,db
=
'
test1
'
)
except
Exception, e:
print
e
sys.exit()
......
8.8. queue — A synchronized queue class¶
queue -- 一个同步队列类
The queue module implements multi-producer, multi-consumer queues. It is especially useful in threaded programming when information must be exchanged safely between multiple threads. The Queue class in this module implemen ......
前一段时间试着用这三种语言简单的写了关于文件拷贝的程序,发现c#和python的api惊人的相似,对于文件的操作这两种语言非常的方便。都没有加异常的处理
C#源代码:
public static void CopyFile(string source, string destination)
& ......
写了几个有关operaminimod的python小程序
firefox->opm书签转换
import re
def pipeiwangzhi(a):
s=[]
pp= re.compile(r'<DT><A HREF="(.*)" ADD_DATE=(.*>)(.*)</A>')
m=pp.search(a)
s1=[]
  ......