DrissionPage解决滑动验证

之前爬取某数据统计平台时遇到了相当严重的反爬机制，采用普通的Selenium也无法绕过。之前尝试过undetected_chromedriver可以使用，但无法设置无头模式，使用起来还是有一定的不美观性。正好近日学习了Drission Page这款相当高效的工具，顺手掏出这个项目重构了一下。填输入数据相当简单：

import os
import cv2
import time
import random
from datetime import datetime
from DrissionPage import ChromiumPage
from DrissionPage import ChromiumOptions

input_code = ""

# 创建页面对象
co = ChromiumOptions().auto_port()  # 指定程序每次使用空闲的端口和临时用户文件夹创建浏览器
co.set_argument('--no-sandbox')  # 无沙盒模式
co.set_argument('--headless=new')  # 无界面系统添加
co.set_argument('--disable-gpu')    # 禁用gpu，提高加载速度
co.set_user_agent("Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/128.0.0.0 Safari/537.36") 

# 创建浏览器窗口
webpage = ChromiumPage(co)


url = ""
webpage.get(url)
webpage.wait(5)

# 选择出口
out_span = webpage.ele('@text()=出口')
out_input = out_span.next('tag:input')
out_input.click()

# 选择币种
currency_span = webpage.ele('@text()=美元')
currency_input = currency_span.next('tag:input')
currency_input.click()

# 选择分月输出
by_month_input = webpage.ele('@name=monthFlag')
by_month_input.click()

# 起止年月
start_select = webpage.ele('@id=startMonth')
end_select = webpage.ele('@id=endMonth')
if start_select.child(-2):
    start_month_option = start_select.child(-2)
else:
    start_month_option = start_select.child(-1)
end_month_option = end_select.child(-1)
start_month_value = start_month_option.attr('value')
end_month_value = end_month_option.attr('value')
start_select.select.by_option(start_month_option)
end_select.select.by_option(start_month_option)

output_field_select_1 = webpage.ele('@id=outerField1')
output_field_select_2 = webpage.ele('@id=outerField2')
output_field_select_1.select.by_value("CODE_TS")
output_field_select_2.select.by_value("ORIGIN_COUNTRY")
output_field_input_1 = webpage.ele("@id=outerValue1")
output_field_input_1.input("85434000,85439090,24041100,24041200,24041990")


do_search_button = webpage.ele('@@tag()=a@@id=doSearch', timeout=2)
do_search_button.click()
time.sleep(1)
# webpage.get_screenshot('test_dp.png')

try:
    webpage.ele('xpath://div[@class="layui-layer-btn"]/a[@class="layui-layer-btn0"]', timeout=2).click()
except:
    pass
time.sleep(1)

这里进入到滑块验证界面，也算是一个难点：

参考了网上的一些方法，通过将缺口图片和背景图用cv2进行一些处理来获取滑动量。但是最后结果并不准确，研究后发现是因为缺口小图并不准确。以另一幅图为例，获取到的小图和背景分别是：

 可以发现直接通过get_screenshot()的方法获取到的小图并不是真的小图。暂时没发现准确获取小图的方法。转换了一下思路，只需要在背景图里找出面积较大的白色区域，就是缺口了。（滑动轨迹模拟的代码源于网络）

def find_blank_region(image):
    gray = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)
    _, binary = cv2.threshold(gray, 240, 255, cv2.THRESH_BINARY)
    contours, _ = cv2.findContours(binary, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)
    contours = [cnt for cnt in contours if cv2.contourArea(cnt) > 500]
    largest_contour = max(contours, key=cv2.contourArea)
    x, y, w, h = cv2.boundingRect(largest_contour)
    return x


# 滑动轨迹模拟 
def generate_track(distance):
    def __ease_out_expo(step):
        return 1 if step == 1 else 1 - pow(2, -10 * step)

    tracks = [[random.randint(20, 60), random.randint(10, 40), 0]]
    count = 30 + int(distance / 2)
    _x, _y = 0, 0
    for item in range(count):
        x = round(__ease_out_expo(item / count) * distance)
        t = random.randint(10, 20)
        if x == _x:
            continue
        tracks.append([x - _x, _y, t])
        _x = x
    tracks.append([0, 0, random.randint(200, 300)])
    times = sum([track[2] for track in tracks])
    return tracks, times

然后运用这两个函数拖动滑块完成验证。这里虽然设置了一直循环，但是大部分情况只需要一次就够了。

while True:
    background_canvas = webpage.ele('xpath://div[@id="captcha"]/canvas', timeout=2)
    background_canvas.get_screenshot('captcha.png')
    background_pic = cv2.imread('captcha.png')
    x_num = find_blank_region(background_pic) * 1.08 
    print(x_num)
    element = webpage.ele('xpath://div[@class="sliderMask"]/div[@class="slider"]')
    element.drag(offset_x=x_num/2, duration=1)
    # webpage.get_screenshot('test_move.png')
    msg = webpage.ele('xpath://div[@id="msg"]', timeout=2).text
    print(msg)
    if msg == '验证通过！':
        time.sleep(2)
        webpage.ele('xpath://div[@class="page-container"]//a[@id="doSearch"]', timeout=2).click()
        break
    time.sleep(3)

最后下载csv：

time.sleep(random.randint(6,8))
download_button = webpage.ele('@@tag()=span@@text()=导出数据')
download_button.click()
confirm_download_button = webpage.ele('@@tag()=a@@class=layui-layer-btn0')
mission = confirm_download_button.click.to_download(r'D:/', 'test2.csv')
mission.wait()
# webpage.get_screenshot('test_dp2.png')