Scrapy：TypeError：__init __（）缺少1個必需的位置參數：'url'

Question

我正在嘗試一個令人毛骨悚然的軟件包https://github.com/clemfromspace/scrapy-selenium 。

我遵循了上面github主頁上的指示。 我開始了一個新的scrapy項目並創建了一個蜘蛛：

from scrapy_selenium import SeleniumRequest

from shutil import which

SELENIUM_DRIVER_NAME = 'firefox'
# SELENIUM_DRIVER_EXECUTABLE_PATH = which('chromedriver')
SELENIUM_DRIVER_EXECUTABLE_PATH = which('geckodriver')
SELENIUM_DRIVER_ARGUMENTS=['-headless']  # '--headless' if using chrome instead of firefox

USER_AGENT = 'Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:48.0) Gecko/20100101 Firefox/48.0'


class MySpider(scrapy.Spider):

    start_urls = ["http://yahoo.com"]
    name = 'test'


    def start_requests(self):
        for url in self.start_urls:

            yield SeleniumRequest(url, self.parse_index_page)


    def parse_index_page(self, response):
        ....

輸出：

 'scrapy.extensions.telnet.TelnetConsole',
 'scrapy.extensions.logstats.LogStats']
2019-07-05 14:14:44 [scrapy.middleware] WARNING: Disabled SeleniumMiddleware: SELENIUM_DRIVER_NAME and SELENIUM_DRIVER_EXECUTABLE_PATH must be set
2019-07-05 14:14:44 [scrapy.middleware] INFO: Enabled downloader middlewares:
['scrapy.downloadermiddlewares.robotstxt.RobotsTxtMiddleware',
 'scrapy.downloadermiddlewares.httpauth.HttpAuthMiddleware',
 ........
 'scrapy.downloadermiddlewares.httpproxy.HttpProxyMiddleware',
 'scrapy.downloadermiddlewares.stats.DownloaderStats']
2019-07-05 14:14:44 [scrapy.middleware] INFO: Enabled spider middlewares:
['scrapy.spidermiddlewares.httperror.HttpErrorMiddleware',
 'scrapy.spidermiddlewares.offsite.OffsiteMiddleware',
 'scrapy.spidermiddlewares.referer.RefererMiddleware',
 'scrapy.spidermiddlewares.urllength.UrlLengthMiddleware',
 'scrapy.spidermiddlewares.depth.DepthMiddleware']
2019-07-05 14:14:44 [scrapy.middleware] INFO: Enabled item pipelines:
[]
2019-07-05 14:14:44 [scrapy.core.engine] INFO: Spider opened
2019-07-05 14:14:44 [scrapy.extensions.logstats] INFO: Crawled 0 pages (at 0 pages/min), scraped 0 items (at 0 items/min)
2019-07-05 14:14:44 [scrapy.extensions.telnet] INFO: Telnet console listening on 127.0.0.1:6023
2019-07-05 14:14:44 [scrapy.core.engine] ERROR: Error while obtaining start requests
Traceback (most recent call last):
  File "....\splashtest\lib\site-packages\scrapy\core\engine.py", line 127, in _next_request
    request = next(slot.start_requests)
  File "E:\ENVS\r3\scrapySelenium\scrapySelenium\spiders\test.py", line 55, in start_requests
    yield SeleniumRequest(url, self.parse_index_page)
  File "....\splashtest\lib\site-packages\scrapy_selenium\http.py", line 32, in __init__
    super().__init__(*args, **kwargs)
TypeError: __init__() missing 1 required positional argument: 'url'
2019-07-05 14:14:44 [scrapy.core.engine] INFO: Closing spider (finished)
2019-07-05 14:14:44 [scrapy.statscollectors] INFO: Dumping Scrapy stats:
{'finish_reason': 'finished',
 'finish_time': datetime.datetime(2019, 7, 5, 18, 14, 44, 74274),
 'log_count/ERROR': 1,
 'log_count/INFO': 9,
 'log_count/WARNING': 1,
 'start_time': datetime.datetime(2019, 7, 5, 18, 14, 44, 66256)}
2019-07-05 14:14:44 [scrapy.core.engine] INFO: Spider closed (finished)

我究竟做錯了什么？

Answer 1

從問題的鏈接中， scrapy_selenium.SeleniumRequest構造函數采用初始參數wait_time ， wait_until ， screenshot和script ，並將其余所有參數傳遞給scrapy.Request構造函數。

發布的代碼使用兩個位置參數實例化SeleniumRequest ，這意味着不會將任何參數傳遞給Request構造函數，從而導致出現問題的錯誤。

要解決此問題，您可以按位置顯式傳遞默認的SeleniumRequest參數：

yield SeleniumRequest(None, None, False, None, url, self.parse_index_page)

或通過關鍵字傳遞Request參數（通常是一種更好的樣式，這既是因為它可以抵抗默認參數的更改，又是因為它可以更輕松地確定正在發生的事情）：

yield SeleniumRequest(url=url, callback=self.parse_index_page)