python笔记：随机数,md5,en/decoder
uuid 生成随机识别号
import uuid for i in range(0,10): print "uuid is :"+ str(uuid.uuid4())
另一种实现
import os import base64 def GetRndStr(): rndByte = os.urandom(6) b64Str = base64.urlsafe_b64encode(rndByte) return b64Str
生成不重复随机序列
import random def get_rnd(max_size, counts): basearr = [x for x in range(max_size)] result = [] max_position = max_size - 1 while counts and max_position: rnd_position = random.randint(0, max_position) result.append(basearr[rnd_position]) basearr[rnd_position] = basearr[max_position] max_position -= 1 counts -= 1 return result for i in range(10): print(get_rnd(1000, 50))
生成snowflake流水号
import datetime import math import threading import time import uuid from random import SystemRandom cryptogen = SystemRandom() # 0位 时间 机器码 random 流水号 # 0 - 0 * 41 - 0 * 10 - 0 * 8 - 0 * 4 class SnowFlake(object): def __init__(self): self._INIT_TIME = 1420041600000 # 2015-01-01 self._last_timestamp = 0 self._WORKER_ID_LEN = 10 self._RAM_LEN = 8 self._FLOW_LEN = 22 - self._WORKER_ID_LEN - self._RAM_LEN self._flow = 0 self._FLOW_MAX = int(math.pow(2, self._FLOW_LEN)) self._lock = threading.Lock() self._worker_id = None self._ram = None def _get_worker_id(self): if not self._worker_id: self._worker_id = uuid.getnode() % int(math.pow(2, self._WORKER_ID_LEN)) return self._worker_id def _generate_ram(self): self._ram = (self._ram + 1) % int(math.pow(2, self._WORKER_ID_LEN)) def _get_ram(self): if not self._ram: self._ram = cryptogen.randrange(0, 100000) % int(math.pow(2, self._RAM_LEN)) return self._ram def generate(self): self._lock.acquire(1) tp = int(time.time() * 1000) tp = tp - self._INIT_TIME if tp < self._last_timestamp: # 处理时间回拔，重新生成ram self._generate_ram() if tp == self._last_timestamp: self._flow += 1 if self._flow > self._FLOW_MAX: raise Exception("flow no overflowed!") else: self._last_timestamp = tp self._flow = 1 ret = 0 ret += tp << (self._WORKER_ID_LEN + self._RAM_LEN + self._FLOW_LEN) ret += self._get_worker_id() << (self._RAM_LEN + self._FLOW_LEN) ret += self._get_ram() << self._FLOW_LEN ret += self._flow self._lock.release() return ret def get_time(self, flow_no): flow_tp = flow_no >> (self._WORKER_ID_LEN + self._RAM_LEN + self._FLOW_LEN) utc_tp = flow_tp + self._INIT_TIME dt = datetime.datetime.fromtimestamp(utc_tp / 1000) return dt def get_worker_id(self, flow_no): worker_id = flow_no >> self._FLOW_LEN + self._RAM_LEN worker_id = worker_id & ((1 << self._WORKER_ID_LEN) - 1) return worker_id def get_ram(self, flow_no): ram = flow_no >> self._FLOW_LEN ram = ram & ((1 << self._RAM_LEN) - 1) return ram if __name__ == '__main__': snowflake = SnowFlake() for i in range(10): flow_no = snowflake.generate() bit_flow_no = '{:064b}'.format(flow_no) dt = snowflake.get_time(flow_no) worker_id = snowflake.get_worker_id(flow_no) ram = snowflake.get_ram(flow_no) # print(flow_no) print("{} n{} n{} " "n{} n{}".format(flow_no, bit_flow_no, dt, worker_id, ram))
加权随机数
import random # 加权随机数 def rnd_power(power_ranks: [int]) -> int: """ 传入权重，随机返回该权重的index :param power_ranks: [10,20,30,40] :return: index of power_rank """ sum_ranks = sum(power_ranks) rnd = random.randint(0, sum_ranks - 1) all_rank = 0 for i, rank in enumerate(power_ranks): all_rank += rank if rnd < all_rank: return i if __name__ == '__main__': result = [0, 0, 0, 0] for i in range(10000): index = rnd_power([10, 20, 30, 40]) result[index] += 1 print(result) # [1000, 2025, 2973, 4002]
2 md5加密
import hashlib md5obj = hashlib.md5() md5obj.update("hello") md5obj.update("world") print md5obj.hexdigest() #md5文件 def CalcMD5(filepath): with open(filepath,'rb') as f: md5obj = hashlib.md5() md5obj.update(f.read()) hash = md5obj.hexdigest() return hash
3 url的编码和解码
import urllib import urlparse data = { 'name':'尹子豪', 'id':'346093' } #返回的是string类型的url data = urllib.urlencode(data) #比较坑，有urlencode没有urldecode。。 print data data = urlparse.urlparse("www.yinzihao.com.cn/index?"+data) #凑个网址，使用parse拆分 print data params=urlparse.parse_qs(data.query,True) #拆分url参数，自动urldecode了，大家不用担心。 print params myname = params['name'][0] #此时可以打印名称了 print myname.decode('utf-8').encode('gbk') #输出的时候使用系统的gbk编码，否则乱码。
py3可以这样
from urllib import parse test = "大猪" test = parse.quote(test) print(test) test = parse.unquote(test) print(test)
4 htmlencoder和decoder
import HTMLParser import cgi def decodeHtml(input): h = HTMLParser.HTMLParser() s = h.unescape(input) return s def encodeHtml(input): s = cgi.escape(input) return s
py3
from html import escape, unescape strs = "<span>></span>" strs = escape(strs) print(strs) strs = unescape(strs) print(strs)
