记一次CSS反爬

目标网址：猫眼电影

主要流程

1. 爬取每一个电影所对应的url
2. 爬取具体电影所对应的源码
3. 解析源码，并下载所对应的字体
4. 使用 fontTools 绘制所对应的数字
5. 运用机器学习的方法识别对应的数字
6. 在源码中用识别的数字替换相应的地方

遇坑经历

• 用 pyquery 的 .text() 方法的时候自动对 html 进行了反转义，替换过程失败，直接打出来一堆乱码，不得已改用 lxml
• 一开始在网上看到很多通过将 woff 字体文件转为 xml 并通过分析 xml 中的 glyf 来判断所对应的汉字，但是看了几个之后发现即使是相同的数字所对应的 x，y值也并不是完全相同
• 对多线程的用法还不是很熟悉

项目列表如下

具体代码如下

Myspider.py

import requests
import fake_useragent
import re
import os
from woffToPng import woff_to_image
from resizeImage import resize_img
from lxml import etree
from html import unescape
from ThreadClass import SpiderThread
from SaveMovieData import SaveInfo
from pyquery import PyQuery as pq
from pprint import pprint
import json
import time


# 用协程实现有点苦难，暂时试一试多线程

# 存储urls
film_urls = []


def verify_img(img_dir):
    api_url = "http://127.0.0.1:6000/b"
    img_to_num = {}
    for file in os.listdir(img_dir):
        file_name = os.path.join(img_dir, file)
        # 重新构建图片大小
        resize_img(file_name, file_name)
        files = {"image_file": ("image_file", open(file_name, "rb"), "application")}
        r = requests.post(url=api_url, files=files, timeout=None)
        if r.status_code == 200:
            # 获得图片的名字，即数字所对应的unicode编码
            num_id = os.path.splitext(file)[0][3:]
            img_to_num[str(int(num_id, 16))] = r.json().get("value")
    return img_to_num


def find_certain_part(html, xpath_format):
    try:
        return html.xpath(xpath_format)[0]
    except Exception:
        return "null"

def parse_data_by_lxml(source_code, img_to_num, saver):
    html = etree.HTML(source_code)

    xpaths = json.loads(open("somexpaths.json", "r").read())

    movie_name = find_certain_part(html, xpaths.get("movie_name"))
    movie_ename = find_certain_part(html, xpaths.get("movie_ename"))
    movie_classes = find_certain_part(html, xpaths.get("movie_classes")).strip()
    movie_length = find_certain_part(html, xpaths.get("movie_length")).strip()
    movie_showtime = find_certain_part(html, xpaths.get("movie_showtime")).strip()


    text_pattern = re.compile('.*?class="stonefont">(.*?)</span>')
    data_to_be_replace = []

    movie_score = find_certain_part(html, xpaths.get("movie_score"))
    movie_score_num = find_certain_part(html, xpaths.get("movie_score_num"))
    if movie_score != "null":
        movie_score = text_pattern.search(etree.tostring(movie_score).decode("utf8")).group(1)
    if movie_score_num != "null":
        movie_score_num = text_pattern.search(etree.tostring(movie_score_num).decode("utf8")).group(1)

    data_to_be_replace.append(movie_score)
    data_to_be_replace.append(movie_score_num)

    movie_box = find_certain_part(html, xpaths.get("movie_box"))
    if movie_box != "null":
        movie_box = text_pattern.search(etree.tostring(movie_box).decode("utf8")).group(1)
    movie_box_unit = find_certain_part(html, xpaths.get("movie_box_unit"))

    data_to_be_replace.append(movie_box)


    # 检查是否是字符串
    for item in data_to_be_replace:
        assert isinstance(item, str)
    # 将 unicode 编码的字符串转化为数字
    for key, value in img_to_num.items():
        new_key = f"&#{key};"
        for i in range(len(data_to_be_replace)):
            if data_to_be_replace[i] == "null":
                continue
            if new_key in data_to_be_replace[i]:
                data_to_be_replace[i] = data_to_be_replace[i].replace(new_key, value)

    movie_score, movie_score_num, movie_box = [unescape(item) for item in data_to_be_replace]
    # 没有评分的当作0
    if movie_score == "null":
        movie_score = "0"
    if movie_box != "null":
        movie_box = movie_box + movie_box_unit.strip()

    movie_brief_info = find_certain_part(html, xpaths.get("movie_brief_info"))
    assert(isinstance(movie_brief_info, str))
    # 这里的实现逻辑有一点问题，因为只是默认第一个是导演
    movie_director, *movie_actors = [item.strip() for item in html.xpath("//body//div[@id='app']//div//div//div//div[@class='tab-content-container']//div//div[@class='mod-content']//div//div//ul//li//div//a/text()")]
    movie_actors = "，".join(movie_actors)

    movie_comments = {}
    try:
        names = html.xpath("//body//div[@id='app']//div//div//div//div//div[@class='module']//div[@class='mod-content']//div[@class='comment-list-container']//ul//li//div//div[@class='user']//span[@class='name']/text()")
        comments = html.xpath("//body//div[@id='app']//div//div//div//div//div[@class='module']//div[@class='mod-content']//div[@class='comment-list-container']//ul//li//div[@class='main']//div[@class='comment-content']/text()")
        assert(len(names) == len(comments))
        for name, comment in zip(names, comments):
            movie_comments[name] = comment
    except Exception:
        pass

    save_id = saver.insert_dict({
        "名称": movie_name,
        "别名": movie_ename,
        "类别": movie_classes,
        "时长": movie_length,
        "上映时间": movie_showtime,
        "评分": float(movie_score),
        "评分人数": movie_score_num,
        "票房": movie_box,
        "简介": movie_brief_info,
        "导演": movie_director,
        "演员": movie_actors,
        "热门评论": movie_comments
    })
    print(f"{save_id} 保存成功")

# 爬取源码，在获得源码之后处理字体文件，处理完字体文件之后进行替换
def get_one_film(url, ua, film_id, saver):
    headers = {
        "User-Agent": ua,
        "Host": "maoyan.com"
    }
    r = requests.get(url=url, headers=headers)
    if r.status_code == 200:
        source_code = r.text
        font_pattern = re.compile("url\(\'(.*?\.woff)\'\)")
        font_url = "http:" + font_pattern.search(r.text).group(1).strip()
        del headers["Host"]
        res = requests.get(url=font_url, headers=headers)
        # 下载字体并进行识别对应
        if res.status_code == 200:
            if os.path.exists(film_id):
                os.system(f"rmdir /s /q {film_id}")
            os.makedirs(film_id)
            woff_path = os.path.join(film_id, "temp.woff")
            img_dir = os.path.join(film_id, "images")
            os.makedirs(img_dir)
            with open(woff_path, "wb") as f:
                f.write(res.content)
            woff_to_image(woff_path, img_dir)
            # 以后试着用协程实现汉字识别
            # 先直接识别
            # 用字典存储，{"img_id": "img_num"}
            img_to_num = verify_img(img_dir)
            # 删除所创建的文件
            os.system(f"rmdir /s /q {film_id}")
            # 对所获得的数据和可以替换的信息进行进一步的处理
            parse_data_by_lxml(source_code, img_to_num, saver)

def get_urls(url, ua, showType, offset):

    base_url = "https://maoyan.com"
    headers = {
        "User-Agent": ua,
        "Host": "maoyan.com"
    }

    params = {
        "showType": showType,
        "offset": offset
    }

    urls = []
    r = requests.get(url=url, headers=headers, params=params)
    if r.status_code == 200:
        doc = pq(r.text)
        for re_url in doc("#app div div[class='movies-list'] dl dd div[class='movie-item'] a[target='_blank']").items():
            urls.append(base_url + re_url.attr("href"))
    film_urls.extend(urls)
    print(f"当前捕获url{len(film_urls)}个")


if __name__ == "__main__":
    # 测试
    ua = fake_useragent.UserAgent()
    tasks_one = []
    try:
        for i in range(68):
            tasks_one.append(SpiderThread(get_urls, args=("https://maoyan.com/films", ua.random, "3", str(30*i))))
        for task in tasks_one:
            task.start()
        for task in tasks_one:
            task.join()
    except Exception as e:
        print(e.args)
    saver = SaveInfo()
    film_ids = [url.split("/")[-1] for url in film_urls]
    print(f"捕获电影url共{len(film_urls)}条")
    tasks_two = []
    count = 0
    try:
        for film_url, film_id in zip(film_urls, film_ids):
            tasks_two.append(SpiderThread(get_one_film, args=(film_url, ua.random, film_id, saver)))
        for task in tasks_two:
            task.start()
            count += 1
            if count % 4 == 0:
                time.sleep(5)
        for task in tasks_two:
            task.join()
    except Exception as e:
        print(e.args)
    print("抓取完毕")

resizeimage.py

from PIL import Image
import os

def resize_img(img_path, write_path):
    crop_size = (120, 200)
    img = Image.open(img_path)
    new_img = img.resize(crop_size, Image.ANTIALIAS)
    new_img.save(write_path, quality=100)

if __name__ == "__main__":
    for root, dirs, files in os.walk("verify_images"):
        for file in files:
            img_path = os.path.join(root, file)
            write_path = os.path.join("resized_images", file)
            resize_img(img_path, write_path)

SaveMovieData.py

import pymongo


class SaveInfo:

    def __init__(self, host="localhost", port=27017, db="MovieSpider",
                 collection="maoyan"):
        self._client = pymongo.MongoClient(host=host, port=port)
        self._db = self._client[db]
        self._collection = self._db[collection]

    def insert_dict(self, data: dict):
        result = self._collection.insert_one(data)
        return result.inserted_id

woffToPng.py

from __future__ import print_function, division, absolute_import
from fontTools.ttLib import TTFont
from fontTools.pens.basePen import BasePen
from reportlab.graphics.shapes import Path
from reportlab.lib import colors
from reportlab.graphics import renderPM
from reportlab.graphics.shapes import Group, Drawing


class ReportLabPen(BasePen):
    """A pen for drawing onto a reportlab.graphics.shapes.Path object."""

    def __init__(self, glyphSet, path=None):
        BasePen.__init__(self, glyphSet)
        if path is None:
            path = Path()
        self.path = path

    def _moveTo(self, p):
        (x, y) = p
        self.path.moveTo(x, y)

    def _lineTo(self, p):
        (x, y) = p
        self.path.lineTo(x, y)

    def _curveToOne(self, p1, p2, p3):
        (x1, y1) = p1
        (x2, y2) = p2
        (x3, y3) = p3
        self.path.curveTo(x1, y1, x2, y2, x3, y3)

    def _closePath(self):
        self.path.closePath()


def woff_to_image(fontName, imagePath, fmt="png"):
    font = TTFont(fontName)
    gs = font.getGlyphSet()
    glyphNames = font.getGlyphNames()
    for i in glyphNames:
        if i == 'x' or i == "glyph00000":  # 跳过'.notdef', '.null'
            continue

        g = gs[i]
        pen = ReportLabPen(gs, Path(fillColor=colors.black, strokeWidth=5))
        g.draw(pen)
        w, h = 600, 1000
        g = Group(pen.path)
        g.translate(0, 200)

        d = Drawing(w, h)
        d.add(g)
        imageFile = imagePath + "/" + i + ".png"
        renderPM.drawToFile(d, imageFile, fmt)

import threading


class SpiderThread(threading.Thread):

    def __init__(self, func, args=()):
        super().__init__()
        self.func = func
        self.args = args

    def run(self) -> None:
        self.result = self.func(*self.args)

    # 相当于没有多线程
    # def get_result(self):
    #     threading.Thread.join(self)
    #     try:
    #         return self.result
    #     except Exception as e:
    #         print(e.args)
    #         return None

somexpaths.json

{
  "movie_name": "//body//div[@class='banner']//div//div[@class='movie-brief-container']//h3/text()",
  "movie_ename": "//body//div[@class='banner']//div//div[@class='movie-brief-container']//div/text()",
  "movie_classes": "//body//div[@class='banner']//div//div[@class='movie-brief-container']//ul//li[1]/text()",
  "movie_length": "//body//div[@class='banner']//div//div[@class='movie-brief-container']//ul//li[2]/text()",
  "movie_showtime": "//body//div[@class='banner']//div//div[@class='movie-brief-container']//ul//li[3]/text()",
  "movie_score": "//body//div[@class='banner']//div//div[@class='movie-stats-container']//div//span[@class='index-left info-num ']//span",
  "movie_score_num": "//body//div[@class='banner']//div//div[@class='movie-stats-container']//div//span[@class='score-num']//span",
  "movie_box": "//body//div[@class='wrapper clearfix']//div//div//div//div[@class='movie-index-content box']//span[@class='stonefont']",
  "movie_box_unit": "//body//div[@class='wrapper clearfix']//div//div//div//div[@class='movie-index-content box']//span[@class='unit']/text()",
  "movie_brief_info": "//body//div[@class='container']//div//div//div//div[@class='tab-content-container']//div//div//div[@class='mod-content']//span[@class='dra']/text()",
  "movie_director_and_actress": "//body//div[@id='app']//div//div//div//div[@class='tab-content-container']//div//div[@class='mod-content']//div//div//ul//li//div//a/text()",
  "commenter_names": "//body//div[@id='app']//div//div//div//div//div[@class='module']//div[@class='mod-content']//div[@class='comment-list-container']//ul//li//div//div[@class='user']//span[@class='name']/text()",
  "commenter_comment": "//body//div[@id='app']//div//div//div//div//div[@class='module']//div[@class='mod-content']//div[@class='comment-list-container']//ul//li//div[@class='main']//div[@class='comment-content']/text()"
}

参考资料

• ReportPen