Pass Scrapy Spider a list of URLs to crawl via .tx

问题:

I'm a little new to Python and very new to Scrapy.

I've set up a spider to crawl and extract all the information I need. However, I need to pass a .txt file of URLs to the start_urls variable.

For exmaple:

class LinkChecker(BaseSpider):
    name = 'linkchecker'
    start_urls = [] #Here I want the list to start crawling a list of urls from a text file a pass via the command line.

I've done a little bit of research and keep coming up empty handed. I've seen this type of example (How to pass a user defined argument in scrapy spider), but I don't think that will work for a passing a text file.

回答1:

Run your spider with -a option like:

scrapy crawl myspider -a filename=text.txt

Then read the file in the __init__ method of the spider and define start_urls:

class MySpider(BaseSpider):
    name = 'myspider'

    def __init__(self, filename=None):
        if filename:
            with open(filename, 'r') as f:
                self.start_urls = f.readlines()

Hope that helps.

回答2:

you could simply read-in the .txt file:

with open('your_file.txt') as f:
    start_urls = f.readlines()

if you end up with trailing newline characters, try:

with open('your_file.txt') as f:
    start_urls = [url.strip() for url in f.readlines()]

Hope this helps

回答3:

If your urls are line seperated

def get_urls(filename):
        f = open(filename).read().split()
        urls = []
        for i in f:
                urls.append(i)
        return urls 

then this lines of code will give you the urls.

回答4:

class MySpider(scrapy.Spider):
    name = 'nameofspider'

    def __init__(self, filename=None):
        if filename:
            with open('your_file.txt') as f:
                self.start_urls = [url.strip() for url in f.readlines()]

This will be your code. It will pick up the urls from the .txt file if they are separated by lines, like, url1 url2 etc..

After this run the command -->

scrapy crawl nameofspider -a filename=filename.txt

Lets say, your filename is 'file.txt', then, run the command -->

scrapy crawl myspider -a filename=file.txt