永利棋牌官方下载-www.55402.com-永利国际唯一指定官网

永利棋牌官方下载提供最新最好玩的真人游戏,www.55402.com是澳门国际娱乐平台官方网站唯一授权会员登录手机版,www.316net,www.366net,516.net,626.net,766.net,www.565.net,www.16.net,bwin62.com,bwin180.com,永利国际唯一指定官网为新老顾客提供更多的精彩娱乐项目,,所有的玩家都可以得到注册送体验金的巨大福利是设身处地为玩家量身订造的经典网站。

Python爬取视频(其实是一篇福利)

Python爬取视频(其实是一篇福利)。窗外下着小雨,作为单身程序员的我逛着逛着发现一篇好东西,Python爬取视频(其实是一篇福利)。来自知乎 你都用 Python 来做什么?Python爬取视频(其实是一篇福利)。的第一个高亮答案。

到上面去看了看,地址都是明文的,得,赶紧开始吧。

下载流式文件,requests库中请求的stream设为True就可以啦,文档在此。

先找一个视频地址试验一下:

# -*- coding: utf-8 -*-
import requests

def download_file(url, path):
    with requests.get(url, stream=True) as r:
        chunk_size = 1024
        content_size = int(r.headers['content-length'])
        print '下载开始'
        with open(path, "wb") as f:
            for chunk in r.iter_content(chunk_size=chunk_size):
                f.write(chunk)


if __name__ == '__main__':
    url = '就在原帖...'
    path = '想存哪都行'
    download_file(url, path)

遭遇当头一棒:

AttributeError: __exit__

这文档也会骗人的么!

看样子是没有实现上下文需要的__exit__方法。既然只是为了保证要让r最后close以释放连接池,那就使用contextlib的closing特性好了:

# -*- coding: utf-8 -*-
import requests
from contextlib import closing

def download_file(url, path):
    with closing(requests.get(url, stream=True)) as r:
        chunk_size = 1024
        content_size = int(r.headers['content-length'])
        print '下载开始'
        with open(path, "wb") as f:
            for chunk in r.iter_content(chunk_size=chunk_size):
                f.write(chunk)

程序正常运行了,不过我盯着这文件,怎么大小不见变啊,到底是完成了多少了呢?还是要让下好的内容及时存进硬盘,还能省点内存是不是:

# -*- coding: utf-8 -*-
import requests
from contextlib import closing
import os

def download_file(url, path):
    with closing(requests.get(url, stream=True)) as r:
        chunk_size = 1024
        content_size = int(r.headers['content-length'])
        print '下载开始'
        with open(path, "wb") as f:
            for chunk in r.iter_content(chunk_size=chunk_size):
                f.write(chunk)
                f.flush()
                os.fsync(f.fileno())

文件以肉眼可见的速度在增大,真心疼我的硬盘,还是最后一次写入硬盘吧,程序中记个数就好了:

def download_file(url, path):
    with closing(requests.get(url, stream=True)) as r:
        chunk_size = 1024
        content_size = int(r.headers['content-length'])
        print '下载开始'
        with open(path, "wb") as f:
            n = 1
            for chunk in r.iter_content(chunk_size=chunk_size):
                loaded = n*1024.0/content_size
                f.write(chunk)
                print '已下载{0:%}'.format(loaded)
                n += 1

结果就很直观了:

已下载2.579129%
已下载2.581255%
已下载2.583382%
已下载2.585508%

心怀远大理想的我怎么会只满足于这一个呢,写个类一起使用吧:

# -*- coding: utf-8 -*-
import requests
from contextlib import closing
import time

def download_file(url, path):
    with closing(requests.get(url, stream=True)) as r:
        chunk_size = 1024*10
        content_size = int(r.headers['content-length'])
        print '下载开始'
        with open(path, "wb") as f:
            p = ProgressData(size = content_size, unit='Kb', block=chunk_size)
            for chunk in r.iter_content(chunk_size=chunk_size):
                f.write(chunk)
                p.output()


class ProgressData(object):

    def __init__(self, block,size, unit, file_name='', ):
        self.file_name = file_name
        self.block = block/1000.0
        self.size = size/1000.0
        self.unit = unit
        self.count = 0
        self.start = time.time()
    def output(self):
        self.end = time.time()
        self.count += 1
        speed = self.block/(self.end-self.start) if (self.end-self.start)>0 else 0
        self.start = time.time()
        loaded = self.count*self.block
        progress = round(loaded/self.size, 4)
        if loaded >= self.size:
            print u'%s下载完成rn'%self.file_name
        else:
            print u'{0}下载进度{1:.2f}{2}/{3:.2f}{4} 下载速度{5:.2%} {6:.2f}{7}/s'.
                  format(self.file_name, loaded, self.unit,
                  self.size, self.unit, progress, speed, self.unit)
            print '%50s'%('/'*int((1-progress)*50))

运行:

下载开始
下载进度10.24Kb/120174.05Kb 0.01% 下载速度4.75Kb/s 
///////////////////////////////////////////////// 
下载进度20.48Kb/120174.05Kb 0.02% 下载速度32.93Kb/s 
/////////////////////////////////////////////////

看上去舒服多了。

下面要做的就是多线程同时下载了,主线程生产url放入队列,下载线程获取url:

# -*- coding: utf-8 -*-
import requests
from contextlib import closing
import time
import Queue
import hashlib
import threading
import os


def download_file(url, path):
    with closing(requests.get(url, stream=True)) as r:
        chunk_size = 1024*10
        content_size = int(r.headers['content-length'])
        if os.path.exists(path) and os.path.getsize(path)>=content_size:
            print '已下载'
            return
        print '下载开始'
        with open(path, "wb") as f:
            p = ProgressData(size = content_size, unit='Kb', block=chunk_size, file_name=path)
            for chunk in r.iter_content(chunk_size=chunk_size):
                f.write(chunk)
                p.output()


class ProgressData(object):

    def __init__(self, block,size, unit, file_name='', ):
        self.file_name = file_name
        self.block = block/1000.0
        self.size = size/1000.0
        self.unit = unit
        self.count = 0
        self.start = time.time()
    def output(self):
        self.end = time.time()
        self.count += 1
        speed = self.block/(self.end-self.start) if (self.end-self.start)>0 else 0
        self.start = time.time()
        loaded = self.count*self.block
        progress = round(loaded/self.size, 4)
        if loaded >= self.size:
            print u'%s下载完成rn'%self.file_name
        else:
            print u'{0}下载进度{1:.2f}{2}/{3:.2f}{4} {5:.2%} 下载速度{6:.2f}{7}/s'.
                  format(self.file_name, loaded, self.unit,
                  self.size, self.unit, progress, speed, self.unit)
            print '%50s'%('/'*int((1-progress)*50))


queue = Queue.Queue()


def run():
    while True:
        url = queue.get(timeout=100)
        if url is None:
            print u'全下完啦'
            break
        h = hashlib.md5()
        h.update(url)
        name = h.hexdigest()
        path = 'e:/download/' + name + '.mp4'
        download_file(url, path)


def get_url():
    queue.put(None)


if __name__ == '__main__':
    get_url()
    for i in xrange(4):
        t = threading.Thread(target=run)
        t.daemon = True
        t.start()

加了重复下载的判断,至于怎么源源不断的生产url,诸位摸索吧,保重身体!

  

本文由永利棋牌官方下载发布于永利棋牌官方下载,转载请注明出处:Python爬取视频(其实是一篇福利)

您可能还会对下面的文章感兴趣: