百度搜索图片下载脚本.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-
# @Author: loveNight
# @Date:   2015-10-28 19:59:24
# @Last Modified by:   loveNight
# @Last Modified time: 2015-11-15 19:43:20


import urllib
import requests
import os
import re
import sys
import time
import threading
from datetime import datetime as dt
from multiprocessing.dummy import Pool
from multiprocessing import Queue


class BaiduImgDownloader(object):

    """百度图片搜索下载工具，目前只支持单个关键词"""

    # 解码网址用的映射表
    str_table = {
        '_z2C$q': ':',
        '_z&e3B': '.',
        'AzdH3F': '/'
    }

    char_table = {
        'w': 'a',
        'k': 'b',
        'v': 'c',
        '1': 'd',
        'j': 'e',
        'u': 'f',
        '2': 'g',
        'i': 'h',
        't': 'i',
        '3': 'j',
        'h': 'k',
        's': 'l',
        '4': 'm',
        'g': 'n',
        '5': 'o',
        'r': 'p',
        'q': 'q',
        '6': 'r',
        'f': 's',
        'p': 't',
        '7': 'u',
        'e': 'v',
        'o': 'w',
        '8': '1',
        'd': '2',
        'n': '3',
        '9': '4',
        'c': '5',
        'm': '6',
        '0': '7',
        'b': '8',
        'l': '9',
        'a': '0'
    }

    re_objURL = re.compile(r'"objURL":"(.*?)".*?"type":"(.*?)"')
    re_downNum = re.compile(r"已下载\s(\d+)\s张图片")
    headers = {
        "User-Agent": "Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/46.0.2490.71 Safari/537.36",
        "Accept-Encoding": "gzip, deflate, sdch",
    }

    def __init__(self, word, dirpath=None, processNum=30):
        if " " in word:
            raise AttributeError("本脚本仅支持单个关键字")
        self.word = word
        self.char_table = {ord(key): ord(value)
                           for key, value in BaiduImgDownloader.char_table.items()}
        if not dirpath:
            dirpath = os.path.join(sys.path[0], 'results')
        self.dirpath = dirpath
        self.jsonUrlFile = os.path.join(sys.path[0], 'jsonUrl.txt')
        self.logFile = os.path.join(sys.path[0], 'logInfo.txt')
        self.errorFile = os.path.join(sys.path[0], 'errorUrl.txt')
        if os.path.exists(self.errorFile):
            os.remove(self.errorFile)
        if not os.path.exists(self.dirpath):
            os.mkdir(self.dirpath)
        self.pool = Pool(30)
        self.session = requests.Session()
        self.session.headers = BaiduImgDownloader.headers
        self.queue = Queue()
        self.messageQueue = Queue()
        self.index = 0  # 图片起始编号，牵涉到计数，不要更改
        self.promptNum = 10  # 下载几张图片提示一次
        self.lock = threading.Lock()
        self.delay = 1.5  # 网络请求太频繁会被封
        self.QUIT = "QUIT"  # Queue中表示任务结束
        self.printPrefix = "**"  # 用于指定在控制台输出

    def start(self):
        # 控制台输出线程
        t = threading.Thread(target=self.__log)
        t.setDaemon(True)
        t.start()
        self.messageQueue.put(self.printPrefix + "脚本开始执行")
        start_time = dt.now()
        urls = self.__buildUrls()
        self.messageQueue.put(
            self.printPrefix + "已获取 %s 个Json请求网址" % len(urls))
        # 解析出所有图片网址，该方法会阻塞直到任务完成
        self.pool.map(self.__resolveImgUrl, urls)
        while self.queue.qsize():
            imgs = self.queue.get()
            self.pool.map_async(self.__downImg, imgs)
        self.pool.close()
        self.pool.join()
        self.messageQueue.put(self.printPrefix + "下载完成！已下载 %s 张图片，总用时 %s" %
                              (self.index, dt.now() - start_time))
        self.messageQueue.put(self.printPrefix + "请到 %s 查看结果！" % self.dirpath)
        self.messageQueue.put(self.printPrefix + "错误信息保存在 %s" % self.errorFile)
        self.messageQueue.put(self.QUIT)

    def __log(self):
        """控制台输出，加锁以免被多线程打乱"""
        with open(self.logFile, "w", encoding="utf-8") as f:
            while True:
                message = self.messageQueue.get()
                if message == self.QUIT:
                    break
                message = str(dt.now()) + " " + message
                if self.printPrefix in message:
                    print(message)
                elif "已下载" in message:
                    # 下载N张图片提示一次
                    downNum = self.re_downNum.findall(message)
                    if downNum and int(downNum[0]) % self.promptNum == 0:
                        print(message)
                f.write(message + '\n')
                f.flush()

    def __getIndex(self):
        """获取文件编号"""
        self.lock.acquire()
        try:
            return self.index
        finally:
            self.index += 1
            self.lock.release()

    def decode(self, url):
        """解码图片URL
        解码前：
        ippr_z2C$qAzdH3FAzdH3Ffl_z&e3Bftgwt42_z&e3BvgAzdH3F4omlaAzdH3Faa8W3ZyEpymRmx3Y1p7bb&mla
        解码后：
        http://s9.sinaimg.cn/mw690/001WjZyEty6R6xjYdtu88&690
        """
        # 先替换字符串
        for key, value in self.str_table.items():
            url = url.replace(key, value)
        # 再替换剩下的字符
        return url.translate(self.char_table)

    def __buildUrls(self):
        """json请求网址生成器"""
        word = urllib.parse.quote(self.word)
        url = r"http://image.baidu.com/search/acjson?tn=resultjson_com&ipn=rj&ct=201326592&fp=result&queryWord={word}&cl=2&lm=-1&ie=utf-8&oe=utf-8&st=-1&ic=0&word={word}&face=0&istype=2nc=1&pn={pn}&rn=60"
        time.sleep(self.delay)
        html = self.session.get(
            url.format(word=word, pn=0), timeout=15).content.decode('utf-8')
        results = re.findall(r'"displayNum":(\d+),', html)
        maxNum = int(results[0]) if results else 0
        urls = [url.format(word=word, pn=x)
                for x in range(0, maxNum + 1, 60)]
        with open(self.jsonUrlFile, "w", encoding="utf-8") as f:
            for url in urls:
                f.write(url + "\n")
        return urls

    def __resolveImgUrl(self, url):
        """从指定网页中解析出图片URL"""
        time.sleep(self.delay)
        html = self.session.get(url, timeout=15).content.decode('utf-8')
        datas = self.re_objURL.findall(html)
        imgs = [Image(self.decode(x[0]), x[1]) for x in datas]
        self.messageQueue.put(self.printPrefix + "已解析出 %s 个图片网址" % len(imgs))
        self.queue.put(imgs)

    def __downImg(self, img):
        """下载单张图片，传入的是Image对象"""
        imgUrl = img.url
        # self.messageQueue.put("线程 %s 正在下载 %s " %
        #          (threading.current_thread().name, imgUrl))
        try:
            time.sleep(self.delay)
            res = self.session.get(imgUrl, timeout=15)
            message = None
            if str(res.status_code)[0] == "4":
                message = "\n%s： %s" % (res.status_code, imgUrl)
            elif "text/html" in res.headers["Content-Type"]:
                message = "\n无法打开图片： %s" % imgUrl
        except Exception as e:
            message = "\n抛出异常： %s\n%s" % (imgUrl, str(e))
        finally:
            if message:
                self.messageQueue.put(message)
                self.__saveError(message)
                return
        index = self.__getIndex()
        # index从0开始
        self.messageQueue.put("已下载 %s 张图片：%s" % (index + 1, imgUrl))
        filename = os.path.join(self.dirpath, str(index) + "." + img.type)
        with open(filename, "wb") as f:
            f.write(res.content)

    def __saveError(self, message):
        self.lock.acquire()
        try:
            with open(self.errorFile, "a", encoding="utf-8") as f:
                f.write(message)
        finally:
            self.lock.release()


class Image(object):

    """图片类，保存图片信息"""

    def __init__(self, url, type):
        super(Image, self).__init__()
        self.url = url
        self.type = type


if __name__ == '__main__':
    print("欢迎使用百度图片下载脚本！\n目前仅支持单个关键词。")
    print("下载结果保存在脚本目录下的results文件夹中。")
    print("=" * 50)
    word = input("请输入你要下载的图片关键词：\n")
    down = BaiduImgDownloader(word)
    down.start()