downtool 的下载参考文章 点这里看
#python3.7
import downtool
a = downtool.down()
a.start()
a.addMission(url,path)
a.stop()
如此,你便创建了一个多线程的下载器,并添加了一个下载任务。
stop()用于控制终止,当然你也可以让他一直运行着,等待后续添加的任务。
执行多线程下载的时候,我们首先需要明确的一点在于:到底是把一个文件分成多分进行下载,还是同时下载多个文件?
这个只需要你掌握了,多线程函数,也就是 python里的 threading 模块,就可以很方便的实现这个需求。
贴上代码:
先看多文件多线程的下载执行函数:
def downLoad(self,url,path,tag):
'''
下载一个大文件/需要对应路径
多线程下载
超时控制
按照区块下载并给出进度
'''
try:
self.logTag("正在下载 "+url+" 为 "+path)
count = 0
count_tmp = 0
time1 = time.time()
header = {'Proxy-Connection':'keep-alive'}
length = float(r.headers['content-length'])
r = requests.get(url, stream=True, headers= header)
f = open(path, 'wb')
for chunk in r.iter_content(chunk_size = 2048):
if chunk:
f.write(chunk)
count += len(chunk)
if time.time()-time1 > 0.25:
p = count / length * 100
speed = self.__formatFloat((count - count_tmp) / 1024 / 1024 / 0.25)
count_tmp = count
self.__changeStatusByTag(tag,'正在下载',path,str(speed)+'MB/s',str(int(count/length*100))+'%')
time1 = time.time()
if not self.key_Keep:
'''
stop函数执行,下载终止。
'''
break
f.close()
return True
except TimeoutError:
self.__changeStatusByTag(tag,'超时',path)
self.logTag("Error<> -path:" +path+"-url:"+url)
return False
except:
self.__changeStatusByTag(tag,'其他错误',path)
self.logTag("Error<> -path:" +path+"-url:"+url)
return False
最后放上全部代码:
import requests
import time
import threading
import os
import json
'''
请记住,人总是本能的排斥没有创造性的工作
请找到自己的意义
Ps:不要把tick设置的太长or太短
'''
def printList(arr):
'''
打印列表
'''
for x in arr:
print(x)
class down():
def __init__(self):
'''
--downtool--
taskList为下载任务队列,格式有两种/待更新
[{
'path':str, -文件保存路径-
'url':str, -目标下载链接-
'isLarge':bool -是否启用大文件下载(downloat_LSize)-
'isDown':bool, -确认是否被下载过-
'isCheck':bool, -确认是否被检查过-
'reDown':int, -重复添加次数/避免重复下载错误文件
},{
'path':str, -文件保存路径-
'url':str, -目标下载链接-
'isLarge':bool -是否启用大文件下载(downloat_LSize,True)-
'isDown':bool, -确认是否被下载过-
'isCheck':bool, -确认是否被检查过-
'reDown':int, -重复添加次数/避免重复下载错误文件
'fileName': str -文件名称(可以用于识别文件对象)-
}]
status为线程状态,格式为
[{
'tag':x, -线程编号-
'now':'wait', -线程状态-
'rate:int -当前任务进度(0~100)-
'goal':'' -线程任务目标(一般为path)-
'speed':'' -当前下载速度(大文件才会有)-
}]
threadList为线程列表,格式为
[{
'name':xxx, -线程类型-
'tag':xx, -线程编号-
'now':xxxx, -当前状态-
'time_start':xxxx, -线程开始时间-
'goal':xxx, -任务路径path-
'thread':threading, -线程时间限制-
'stop':bool -(目前)用于控制大文件下载的暂停-
}]
--变量说明--
header : header(如果需要的话,这个目前还没有用上)
status : 线程状态-list
helper : 守护线程-thread
thread
-List : 线程列表-list
-MaxNum : 最大线程数量
task
-List : 任务队列-list
-Key : 当前已创建下载的任务数量
-CheckKey:当前已检查的任务数量
-num : 当前任务列表的长度(任务数量)
key_Keep : bool/设置为False停止创建新的下载进程
lock : 进程锁/目前还没有什么用
log : 错误输出控制
tick : 状态更新间隔
timeOut : 超时时间
reDownMax : 最大重复下载次数
file_history: 下载历史记录-json
chunk_size :文件下载时单个区块的大小
block_size :大文件下载时拆分出的任务单元的大小
path : 默认路径(~/desktop/downloadByTool/)
--变量说明--
'''
self.stopWhenFinish = True
self.header = []
self.status = []
self.helper = {}
self.threadList = []
self.threadMaxNum = 10
self.taskList = []
self.taskKey = 0
self.taskCheckKey = 0
self.taskNum = 0
self.key_Keep = True
self.lock = threading.Lock()
self.log = False
self.tick = 0.5
self.timeOut = 4
self.reDownMax = 10
self.file_history = 'DownToolHistory.json'
self.chunk_size = 10240
self.block_size = 1024*1024*5 # 1024^2*10
self.path = self.__getDesktopPath()+'/downloadByDowntool/'
def start(self,stopWhenFinish = False):
'''
启动
'''
self.mkdirFile(self.path)
self.stopWhenFinish = stopWhenFinish
timeStart = time.time()
for x in range(self.threadMaxNum):
status = {
'name':'',
'tag':x,
'now':'wait',
'time_start':str(timeStart),
'goal':'',
'thread':''
}
self.threadList.append(status)
status = {
'tag':x,
'now':'wait',
'goal':''
}
self.status.append(status)
for x in self.threadList:
self.workProcess_create(x)
self.helper = _downTool_commonThread(self.statusPrint,(),'0')
self.helper.start()
def stop(self):
'''
暂停函数
'''
self.key_Keep = False
self.saveHistory()
def statusPrint(self):
'''
下载状态显示(暂定)
目前使用终端显示,希望之后可以改成用vue的界面显示
留个坑
'''
while(self.key_Keep):
self.clearShellinWin()
print('当前状态:',end=' : ')
print(self.helper)
print('任务总量:'+str(self.taskNum)+'||当前指针:'+str(self.taskKey))
if self.log:
for i in range(len(self.threadList)):
print(i,end=' : ')
print(self.threadList[i])
for x in range(len(self.status)):
print('线程<'+str(x)+'>',end=' : ')
print(self.status[x])
time.sleep(self.tick)
def workProcess_create(self,threadStatus):
'''
创建工作进程/下载
'''
if self.key_Keep:
tag = threadStatus['tag']
self.threadList[threadStatus['tag']]['thread'] = _downTool_commonThread(self.workProcess,(tag,'name'),'name'+str(threadStatus['tag']))
self.threadList[threadStatus['tag']]['thread'].start()
else:
self.logTag('工作进程创建终止')
def workProcess(self,tag,name):
'''
工作进程
自动询问任务
下载失败之后自动把失败任务重新添加到下载队列中
'''
deal = {}
while(self.key_Keep):
# while(self.taskKey<=self.taskNum):
self.lock.acquire()
if self.taskNum==0:
self.lock.release()
self.__changeStatusByTag(tag,'等待任务','')
time.sleep(1)
continue
elif self.taskKey>=self.taskNum:
self.lock.release()
self.__changeStatusByTag(tag,'等待任务','')
time.sleep(1)
continue
else:
deal = self.taskList[self.taskKey]
self.taskKey = self.taskKey + 1
self.lock.release()
self.__changeStatusByTag(tag,'开始下载',deal['path'])
if self.__downLoadStart(deal['url'],deal['path'],tag,deal['isLarge'],deal):
self.__changeStatusByTag(tag,'完成下载',deal['path'])
continue
else:
if deal['isLarge']==False:
self.addMission(deal['url'],path = deal['path'],reDown = deal['reDown']+1,isLarge = deal['isLarge'])
elif deal['isLarge']==True:
self.addMission(deal['url'],path = deal['path'],fileName=deal['fileName'],reDown=deal['reDown']+1,isLarge = deal['isLarge'])
def __changeStatusByTag(self,tag,status_tag1,status_tag2,status_speed='无',status_process =' '):
'''
修改进程状态
'''
for x in range(len(self.status)):
if self.status[x]['tag']==tag:
self.status[x]['now']= str(status_tag1)
self.status[x]['goal']= str(status_tag2)
self.status[x]['speed'] = str(status_speed)
self.status[x]['rate'] = str(status_process)
def getHistory(self):
'''
读取下载历史
留个坑/下载大文件时,如何读取下载记录
'''
try:
data = {}
with open(self.file_history,'r') as fileObj:
data = json.load(fileObj)
self.taskKey = data['key']
self.taskList = data['list']
self.taskNum = len(self.taskList)
if self.taskKey>self.taskNum:
raise ''
except :
self.logTag('error<>:读取失败//path' +self.file_history)
def saveHistory(self):
'''
保存下载历史
'''
try:
data = {
'key':self.taskKey,
'list':self.taskList
}
with open(self.file_history,'w') as fileObj:
json.dump(data,fileObj)
except:
self.logTag("error<>:保存失败//path=" +self.file_history)
def addMission(self,url,path = '',fileName = '',reDown = 0,isLarge = False):
'''
加入一个新的任务/小任务
and
大文件下载预先处理函数
目前的大文件的下载地址统一(默认)在 ~/downloadByDowntool/大文件文件名/ 路径下
1. 取出文件名称
2. 在downloadbydowntool文件夹下创建一个该文件名的文件夹,并在文件夹内创建区块拆分记录
3. 将每一个区块的下载任务添加进self.taskList中
很遗憾,目前这个函数会变得相当冗杂
希望在之后可以修改
留个坑
'''
try:
if isLarge:
if fileName == '':
fileName = url.split('/')[-1].split('.')[0]
if path == '':
path = self.path+fileName
self.mkdirFile(path)
BlockList = self.__getFileSizeByRequest(url)
self.__saveAJson(path+'/'+fileName+'.json',{
'fileName':fileName,
'path':path,
'isDown':0,
'BlockList':BlockList,
'filePath':[]
})
self.logTag(BlockList)
for x in BlockList:
task = {
'path':path,
'url':url,
'fileName':fileName,
'isLarge':True,
'isCheck':False,
'isDown':False,
'reDown':reDown,
'blockTag':x['blockTag'],
'start':x['start'],
'end':x['end'],
}
self.logTag(task)
self.taskList.append(task)
self.taskNum = len(self.taskList)
else:
if path == '':
self.logTag("error : 任务添加失败 reDown:"+str(reDown)+' url: '+url+' path: '+path)
return False
if reDown<self.reDownMax:
path = str(path)
url = str(url)
self.taskNum = self.taskNum + 1
task = {
'path':path,
'url':url,
'isLarge':isLarge,
'isCheck':False,
'isDown':False,
'reDown':reDown
}
self.taskList.append(task)
return True
else:
self.logTag("error : 任务重复添加 reDown:"+str(reDown)+' url: '+url+' path: '+path)
return False
except:
self.logTag("error : 任务添加失败 reDown:"+str(reDown)+' url: '+url+' path: '+path)
return False
else:
self.logTag("success : 任务添加成功 reDown:"+str(reDown)+' url: '+url+' path: '+path)
return True
def __downLoadStart(self,url,path,tag,isLarge,deal):
'''
下载前判断
'''
self.logTag(deal)
if isLarge == True:
start = deal['start']
end = deal['end']
path = path+'/'+deal['fileName']
return self.downLoad_LSize(url,path,tag,start,end)
else:
return self.downLoad(url,path,tag)
def downLoad(self,url,path,tag):
'''
下载一个大文件/需要对应路径
多线程下载
超时控制
按照区块下载并给出进度
留个坑/使用更加优雅的with
'''
try:
self.logTag("正在下载 "+url+" 为 "+path)
count = 0
count_tmp = 0
time1 = time.time()
header = {'Proxy-Connection':'keep-alive'}
length = float(r.headers['content-length'])
r = requests.get(url, stream=True, headers= header)
f = open(path, 'wb')
for chunk in r.iter_content(chunk_size = 2048):
if chunk:
f.write(chunk)
count += len(chunk)
if time.time()-time1 > 0.25:
p = count / length * 100
speed = self.__formatFloat((count - count_tmp) / 1024 / 1024 / 0.25)
count_tmp = count
self.__changeStatusByTag(tag,'正在下载',path,str(speed)+'MB/s',str(int(count/length*100))+'%')
time1 = time.time()
if not self.key_Keep:
'''
stop函数执行,下载终止。
'''
break
f.close()
return True
except TimeoutError:
self.__changeStatusByTag(tag,'超时',path)
self.logTag("Error<> -path:" +path+"-url:"+url)
return False
except:
self.__changeStatusByTag(tag,'其他错误',path)
self.logTag("Error<> -path:" +path+"-url:"+url)
return False
def downLoad_LSize(self,url,path,tag,start,end):
'''
使用分块下载的方式下载一个大文件
下载之后需要在对应的json文件内修改下载属性
'''
try:
header = {'Proxy-Connection':'keep-alive','range':'bytes='+ str(start) +'-'+ str(end)}
r = requests.get(url, stream=True, headers = header)
length = float(r.headers['content-length'])
count = 0
count_tmp = 0
time1 = time.time()
F_start = start
self.__checkFile_WithCreate(path)
for chunk in r.iter_content(chunk_size=self.chunk_size):
if chunk:
self.lock.acquire()
with open(path, 'rb+') as f:
f.seek(F_start,0)
f.write(chunk)
self.lock.release()
F_start += len(chunk)
count += len(chunk)
if time.time()-time1 > 0.25:
p = count / length * 100
speed = self.__formatFloat((count - count_tmp) / 1024 / 1024 / 0.25)
count_tmp = count
self.__changeStatusByTag(tag,'正在下载',path,str(speed)+'MB/s',str(int(count/length*100))+'%')
time1 = time.time()
return True
except TimeoutError:
self.__changeStatusByTag(tag,'超时',path)
self.logTag("Error<> -path:" +path+"-url:"+url)
return False
except:
self.__changeStatusByTag(tag,'其他错误',path)
self.logTag("Error<> -path:" +path+"-url:"+url)
return False
def writeFile(self,start,data,path):
try:
with open(path,'ab+') as f:
f.seek(start)
f.write(data)
except:
return False
def __formatFloat(self,num):
'''
用于获取限位的float数值
'''
return '{:.2f}'.format(num)
def mkdirFile(self,path):
'''
创建文件/多用于创建文件夹
'''
try:
path = self.__pathDeal(path)
if not os.path.exists(path):
os.makedirs(path)
return True
else:
return False
except:
self.logTag("Error:"+str(time.time())+":mkdirFile:"+path)
def __saveAJson(self,path,data):
'''
写入一个json文件
'''
try:
with open(path,'w') as fileObj:
json.dump(data,fileObj)
return True
except:
return False
def __getAJson(self,path):
'''
读取一个json文件
'''
try:
data = {}
with open(path,'r') as fileObj:
data = json.load(fileObj)
return data
except :
return False
def __getFileSizeByRequest(self,url):
'''
获取待下载文件的大小
返回按照区块(self.block_size)划分的列表
'''
r1 = requests.get(url, stream=True, verify=False)
size = int(r1.headers['Content-Length'])
i = 0
sizeList = []
tag = 0
while(i<size):
if i+self.block_size<size:
sizeList.append({
'start':i,
'end':i+self.block_size,
'isDown':False,
'blockTag':tag
})
else:
sizeList.append({
'start':i,
'end':size,
'isDown':False,
'blockTag':tag
})
tag+=1
i+=self.block_size
i+=1
return sizeList
def __checkFile(self,path):
'''
单个下载文件的检查
只能用于检查文件是否存在,并无检查文件大小
'''
try:
path = self.__pathDeal(path)
if os.path.exists(path):
return True
else:
return False
except:
self.logTag("Error:"+str(time.time())+":checkFile:"+path)
return False
def __checkFile_WithCreate(self,path):
'''
检查文件是否存在
若不存在则创建
'''
if self.__checkFile(path):
# self.log(path)
# print(path)
return True
else:
f = open(path,'w')
f.close()
return True
def __checkFileSize(self,path):
'''
检查文件的大小
'''
if self.__checkFile(path):
size = os.path.getsize(path)
return size
else:
return False
def __getDesktopPath(self):
'''
获取桌面路径
'''
return os.path.join(os.path.expanduser('~'),"Desktop")+'/'
def __pathDeal(self,path):
'''
下载路径处理
'''
path = path.strip()
path = path.rstrip()
return path
def __getFileTypeByUrl(self,fileName,url):
'''
处理文件类型/通过url
'''
return str(fileName+url.split('.')[-1])
def logTag(self,log):
'''
可关闭的输出
'''
if self.log == True:
print(str(log))
def clearShellinWin(self):
'''
清屏/终端用 win
'''
os.system("cls")
class _downTool_commonThread(threading.Thread):
'''
_downTool_公共线程工具
'''
def __init__(self,func,args,name):
threading.Thread.__init__(self)
self.func = func
self.args = args
self.name = name
def run(self):
print('线程--<<'+self.name+'>>--已启动')
self.func(*self.args)
print('线程--<<'+self.name+'>>--已结束')