支持python的字模 python自带字体

在爬取网站抓取数据的过程中，有时会遇到这样一种情况：网页浏览正常，开发者模式（F12）查看原来没之后发现关键数据乱码，当然爬取下来的结果也是乱码。这种反爬策略一般称之为字体反爬。

以58同城为例：

用浏览器随便打开58同城的一个页面，F12调出开发者调试窗口：

网页显示正常，调试窗口出现的内容与页面显示不符。

回到网页上，右键查看网页源代码，搜索base64关键字，可以看到一大串用base64加密的字符，复制逗号之后单引号之前的字符串：

编写Python代码，用base64把复制下来的加密字符串进行解码并保存为58.ttf：

import base64

font_face = "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"

b = base64.b64decode(font_face)
with open('58.ttf', 'wb') as f:
    f.write(b)

用Python第三方库fontTools来获取字体映射表。

安装fontTools：

pip install fontTools

先来看下ttf文件中有哪些信息，直接打开ttf文件那当然看不了，把它转换成xml文件就可以查看了：

from fontTools.ttLib import TTFont

font = TTFont('58.ttf')  # 打开刚才保存在本地的58.ttf文件
font.saveXML('58.xml')  # 转换并保存为xml

打开58.xml文件，可以看到类似html标签的文件结构：

点开GlyphOrder标签，可以看到id和name：

点开cmap标签，是code和name的对应关系：

用代码来获取编码和name的对应关系：

from fontTools.ttLib import TTFont

font = TTFont('58.ttf')  # 打开本地的ttf文件
bestcmap = font['cmap'].getBestCmap()
print(bestcmap)

输出如下：

{38006: 'glyph00007', 38287: 'glyph00005', 39228: 'glyph00009', 39499: 'glyph00004', 40506: 'glyph00008', 40611: 'glyph00003', 40804: 'glyph00006', 40850: 'glyph00002', 40868: 'glyph00001', 40869: 'glyph00010'}

输出的是一个字典，key是编码的int型（十进制）

我们把这个字典转一下，变成编码和正常字体的映射关系：

import re
from fontTools.ttLib import TTFont

font = TTFont('58.ttf')  # 打开本地的ttf文件
bestcmap = font['cmap'].getBestCmap()
newmap = dict()
for key in bestcmap.keys():
    value = int(re.search(r'(\d+)', bestcmap[key]).group(1)) - 1
    key = hex(key)
    newmap[key] = value
print(newmap)

输出如下：

{'0x9476': 6, '0x958f': 4, '0x993c': 8, '0x9a4b': 3, '0x9e3a': 7, '0x9ea3': 2, '0x9f64': 5, '0x9f92': 1, '0x9fa4': 0, '0x9fa5': 9}

现在就可以把页面上的自定义字体替换成正常字体，再解析需要的字段，Scrapy实现的全部代码如下：

import scrapy
from items import Com58FanLoder
from items import FanInfoItem
import re, base64, io
from scrapy.selector import Selector
from fontTools.ttLib import TTFont
class Com58Spider(scrapy.Spider):
	# 只列出parse函数
    def parse_fan(self, response):
        # 获取加密字符串
        base64_str = re.search(r"base64,(.*?)'\)", response.text).group(1)
        b = base64.b64decode(base64_str)
        font = TTFont(io.BytesIO(b))
        bestcmap = font['cmap'].getBestCmap()
        newmap = dict()
        for key in bestcmap.keys():
            value = int(re.search(r'(\d+)', bestcmap[key]).group(1)) - 1
            key = hex(key)
            newmap[key] = value
        # 把页面上自定义字体替换成正常字体
        __response = response.text
        for key, value in newmap.items():
            key = key.replace('0x', '&#x') + ';'
            if key in __response:
                __response = __response.replace(key, str(value))

        selector = Selector(text=__response)

        # 与上面分开，上面解析字体反爬
        item_loader = Com58FanLoder(item=FanInfoItem(), response=response)
        item_loader.add_xpath('house_title', '//div[@class="house-title"]/h1/text()')
        item_loader.add_value('house_price', selector.xpath('//p[@class="house-basic-item1"]/span[1]').extract_first())
        item_loader.add_value('unit_price', selector.xpath('//p[@class="house-basic-item1"]/span[2]/text()').
                              extract_first().replace('\xa0', ''))  # replace('\xa0', '')的原因是因为有一个空格，导致显示不正常，直接剔除即可

解析结果，圈出的部分就是上述代码的提取结果：

当然，给出用requests解析的代码，感谢python解析字体反爬博主：

import requests
import re, base64, io
from lxml import etree
from fontTools.ttLib import TTFont

# 待解析的url
url = r'https://sz.58.com/chuzu/'

headers = {
    'User-Agent':'Mozilla/5.0 (compatible; Baiduspider/2.0; +http://www.baidu.com/search/spider.html)'
}
response = requests.get(url=url, headers=headers)
# 获取加密字符串
base64_str = re.search("base64,(.*?)'\)", response.text).group(1)
b = base64.b64decode(base64_str)
font = TTFont(io.BytesIO(b))
bestcmap = font['cmap'].getBestCmap()
newmap = dict()
for key in bestcmap.keys():
    value = int(re.search(r'(\d+)', bestcmap[key]).group(1)) - 1
    key = hex(key)
    newmap[key] = value
# 把页面上自定义字体替换成正常字体
response_ = response.text
for key,value in newmap.items():
    key_ = key.replace('0x','&#x') + ';'
    if key_ in response_:
        response_ = response_.replace(key_,str(value))
# 获取标题
rec = etree.HTML(response_)
lis = rec.xpath('//ul[@class="listUl"]/li')
for li in lis:
    title = li.xpath('./div[@class="des"]/h2/a/text()')
    if title:
        title = title[0]
        print(title)

---