🕷 Python SEO Crawler / Spider
A customizable crawler to analyze SEO and content of pages and websites.
This is provided by the crawl() function which is customized for SEO and
content analysis usage, and is highly configurable. The crawler uses
Scrapy so you get all the power that it provides in
terms of performance, speed, as well as flexibility and customization.
There are two main approaches to crawl:
Discovery (spider mode): You know the website to crawl, so you provide a
url_list(one or more URLs), and you want the crawler to go through the whole website(s) by following all available links.Pre-determined (list mode): You have a known set of URLs that you want to crawl and analyze, without following links or discovering new URLs.
Discovery Crawling Approach
The simplest way to use the function is to provide a list of one or more URLs and the crawler will go through all of the reachable pages.
>>> import advertools as adv
>>> adv.crawl('https://example.com', 'my_output_file.jl', follow_links=True)
That's it! To open the file:
>>> import pandas as pd
>>> crawl_df = pd.read_json('my_output_file.jl', lines=True)
What this does:
Check the site's robots.txt file and get the crawl rules, which means that your crawl will be affected by these rules and the user agent you are using. Check the details below on how to change settings and user agents to control this.
Starting with the provided URL(s) go through all links and parse pages.
For each URL extract the most important SEO elements.
Save them to
my_output_file.jl.The column headers of the output file (once you import it as a DataFrame) would be the names of the elements (title, h1, h2, etc.).
Jsonlines is the supported output format because of its flexibility in allowing different values for different scraped pages, and appending indepentent items to the output files.
Note
When the crawler parses pages it saves the data to the specified file by
appending, and not overwriting. Otherwise it would have to store all the
data in memory, which might crash your computer. A good practice is to have
a separate output_file for every crawl with a descriptive name
sitename_crawl_YYYY_MM_DD.jl for example. If you use the same file you
will probably get duplicate data in the same file.
Extracted On-Page SEO Elements
The names of these elements become the headers (column names) of the
output_file.
Element |
Remarks |
|---|---|
url |
The response URL that was actually crawled. This might be different from the rquested URL in case of a redirect for example. Please check the |
title |
The <title> tag(s) |
viewport |
The viewport meta tag if available |
charset |
The charset meta tag if available |
meta_desc |
Meta description |
canonical |
The canonical tag if available |
alt_href |
The href attribute of rel=alternate tags |
alt_hreflang |
The language codes of the alternate links |
og:* |
Open Graph data |
twitter:* |
Twitter card data |
jsonld_* |
JSON-LD data if available. In case multiple snippets occur, the respective column names will include a number to distinguish them, jsonld_1_{item_a}, jsonld_1_{item_b}, etc. Note that the first snippet will not contain a number, so the numbering starts with "1", starting from the second snippet. The same applies to OG and Twitter cards. |
h1...h6 |
<h1> through <h6> tag(s), whichever is available |
links_url |
The URLs of the links on the page |
links_text |
The link text (anchor text) |
links_nofollow |
Boolean, whether or not the link is a nofllow link. Note that this only tells if the link itself contains a rel="nofollow" attribute. The page might indicate "nofollow" using meta robots or X-Robots-Tag, which you have to check separately. |
nav_links_text |
The anchor text of all links in the <nav> tag if available |
nav_links_url |
The links in the <nav> tag if available |
header_links_text |
The anchor text of all links in the <header> tag if available |
header_links_url |
The links in the <header> tag if available |
footer_links_text |
The anchor text of all links in the <footer> tag if available |
footer_links_url |
The links in the <footer> tag if available |
body_text |
The text in the <p>, <span>, and <li> tags within <body> |
size |
The page size in bytes |
download_latency |
The amount of time it took to get the page HTML, in seconds. |
download_timout |
The amount of time (in secs) that the downloader will wait before timing out. Defaults to 180. |
redirect_times |
The number of times the pages was redirected if available |
redirect_ttl |
The default maximum number of redirects the crawler allows |
redirect_urls |
The chain of URLs from the requested URL to the one actually fetched |
redirect_reasons |
The type of redirection(s) 301, 302, etc. |
depth |
The depth of the current URL, relative to the first URLs where crawling started. The first pages to be crawled have a depth of zero, pages linked from there, a depth of one, etc. |
status |
Response status code (200, 404, etc.) |
img_* |
All available |
ip_address |
IP address |
crawl_time |
Date and time the page was crawled |
resp_headers_* |
All available response headers (last modified, server, etc.) |
request_headers_* |
All available request headers (user-agent, encoding, etc.) |
Note
All elements that may appear multiple times on a page (like heading tags, or images, for example), will be joined with two "@" signs @@. For example, "first H2 tag@@second H2 tag@@third tag" and so on. Once you open the file, you simply have to split by @@ to get the elements as a list.
Here is a sample file of a crawl of this site (output truncated for readability):
>>> import pandas as pd
>>> site_crawl = pd.read_json('path/to/file.jl', lines=True)
>>> site_crawl.head()
url title meta_desc h1 h2 h3 body_text size download_timeout download_slot download_latency redirect_times redirect_ttl redirect_urls redirect_reasons depth status links_href links_text img_src img_alt ip_address crawl_time resp_headers_date resp_headers_content-type resp_headers_last-modified resp_headers_vary resp_headers_x-ms-request-id resp_headers_x-ms-version resp_headers_x-ms-lease-status resp_headers_x-ms-blob-type resp_headers_access-control-allow-origin resp_headers_x-served resp_headers_x-backend resp_headers_x-rtd-project resp_headers_x-rtd-version resp_headers_x-rtd-path resp_headers_x-rtd-domain resp_headers_x-rtd-version-method resp_headers_x-rtd-project-method resp_headers_strict-transport-security resp_headers_cf-cache-status resp_headers_age resp_headers_expires resp_headers_cache-control resp_headers_expect-ct resp_headers_server resp_headers_cf-ray resp_headers_cf-request-id request_headers_accept request_headers_accept-language request_headers_user-agent request_headers_accept-encoding request_headers_cookie
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66 https://advertools.readthedocs advertools.url_builders — Pyt NaN Source code for advertools.url NaN NaN © Copyright 2020, Eli NaN NaN advertools.readthedocs.io NaN NaN NaN NaN NaN NaN NaN ../../index.html@@../../readme @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ NaN NaN 104.17.32.82 2020-05-21 10:39:39 Thu, 21 May 2020 10:39:38 GMT text/html Wed, 20 May 2020 12:26:36 GMT Accept-Encoding d99f2368-c01e-006f-18c3-2ef5ef 2009-09-19 unlocked BlockBlob * Nginx-Proxito-Sendfile web00007a advertools latest /proxito/media/html/advertools advertools.readthedocs.io path subdomain max-age=31536000; includeSubDo HIT NaN Thu, 21 May 2020 11:39:38 GMT public, max-age=3600 max-age=604800, report-uri="ht cloudflare 596dacbbb8afd437-BUD 02d86a494f0000d437b828b2000000 text/html,application/xhtml+xm en Mozilla/5.0 (Windows NT 10.0; gzip, deflate __cfduid=d76b68d148ddec1efd004
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68 https://advertools.readthedocs advertools.ad_from_string — P NaN Source code for advertools.ad_ NaN NaN © Copyright 2020, Eli NaN NaN advertools.readthedocs.io NaN NaN NaN NaN NaN NaN NaN ../../index.html@@../../readme @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ NaN NaN 104.17.32.82 2020-05-21 10:39:39 Thu, 21 May 2020 10:39:39 GMT text/html Wed, 20 May 2020 12:26:36 GMT Accept-Encoding b0aef497-801e-004a-1647-2f6d5c 2009-09-19 unlocked BlockBlob * Nginx-Proxito-Sendfile web00007k advertools latest /proxito/media/html/advertools advertools.readthedocs.io path subdomain max-age=31536000; includeSubDo HIT NaN Thu, 21 May 2020 11:39:39 GMT public, max-age=3600 max-age=604800, report-uri="ht cloudflare 596dacbd980cd423-BUD 02d86a4a7f0000d423209db2000000 text/html,application/xhtml+xm en Mozilla/5.0 (Windows NT 10.0; gzip, deflate __cfduid=d76b68d148ddec1efd004
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70 https://advertools.readthedocs advertools.emoji — Python NaN Source code for advertools.emo NaN NaN © Copyright 2020, Eli NaN NaN advertools.readthedocs.io NaN NaN NaN NaN NaN NaN NaN ../../index.html@@../../readme @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ NaN NaN 104.17.32.82 2020-05-21 10:39:40 Thu, 21 May 2020 10:39:39 GMT text/html Wed, 20 May 2020 12:26:36 GMT Accept-Encoding 2ad504a1-101e-000b-03c3-2e454f 2009-09-19 unlocked BlockBlob * Nginx-Proxito-Sendfile web000079 advertools latest /proxito/media/html/advertools advertools.readthedocs.io path subdomain max-age=31536000; includeSubDo HIT NaN Thu, 21 May 2020 11:39:39 GMT public, max-age=3600 max-age=604800, report-uri="ht cloudflare 596dacbd9fb97e9e-BUD 02d86a4a7f00007e9edb13a2000000 text/html,application/xhtml+xm en Mozilla/5.0 (Windows NT 10.0; gzip, deflate __cfduid=d76b68d148ddec1efd004
Pre-Determined Crawling Approach (List Mode)
Sometimes you might have a fixed set of URLs for which you want to scrape and analyze SEO or content performance. Some ideas:
SERP Data
Let's say you just ran serp_goog and got a bunch of top-ranking pages that you would like to analyze, and see how that relates to their SERP ranking.
You simply provide the url_list parameter and again specify the
output_file. This will only crawl the specified URLs, and will not follow
any links.
Now you have the SERP DataFrame, as well as the crawl output file. All you have to do is to merge them by the URL columns, and end up with a richer dataset
News Articles
You want to follow the latest news of a certain publication, and you extract their latest news URLs from their news sitemap using sitemap_to_df . You provide those URLs and crawl them only.
Google Analytics / Google Search Console
Since they provide reports for URLs, you can also combine them with the ones crawled and end up with a better perspective. You might be interested in knowing more about high bounce-rate pages, pages that convert well, pages that get less traffic than you think they should and so on. You can simply export those URLs and crawl them.
Any tool that has data about a set of URLs can be used.
Again running the function is as simple as providing a list of URLs, as well as a filepath where you want the result saved.
>>> adv.crawl(url_list, 'output_file.jl', follow_links=False)
The difference between the two approaches, is the simple parameter
follow_links. If you keep it as False (the default), the crawler
will only go through the provided URLs. Otherwise, it will discover pages by
following links on pages that it crawls. So how do you make sure that the
crawler doesn't try to crawl the whole web when follow_links is True?
The allowed_domains parameter gives you the ability to control this,
although it is an optional parameter. If you don't specify it, then it will
default to only the domains in the url_list and their sub-domains if any.
It's important to note that you have to set this parameter if you want to only
crawl certain sub-domains.
Custom Extraction with CSS and XPath Selectors
The above approaches are generic, and are useful for exploratory SEO audits and the output is helpful for most cases.
But what if you want to extract special elements that are not included in the default output? This is extremely important, as there are key elements on pages that you need to additionally extract and analyze. Some examples might be tags, prices, social media shares, product price or availability, comments, and pretty much any element on a page that might be of interest to you.
For this you can use two special parameters for CSS and/or XPath selectors. You simply provide a dictionary {'name_1': 'selector_1', 'name_2': 'selector_2'} where the keys become the column names, and the values (selectors) will be used to extract the required elements.
I mostly rely on SlectorGadget which is a really great tool for getting the CSS/XPath selecotrs of required elements. In some pages it can get really tricky to figure that out. Other resources for learning more about selectors:
Once you have determined the elements that you want to extract and figured out
what their names are going to be, you simply pass them as arguments to
css_selectors and/or xpath_selectors as dictionaries, as decribed
above.
Let's say you want to extract the links in the sidebar of this page. By default you would get all the links from the page, but you want to put those in the sidebar in a separate column. It seems that the CSS selector for them is .toctree-l1 .internal, and the XPath equivalent is //*[contains(concat( " ", @class, " " ), concat( " ", "toctree-l1", " " ))]//*[contains(concat( " ", @class, " " ), concat( " ", "internal", " " ))]. Note that this selects the element (the whole link object), which is not typically what you might be interested in.
So with CSS you need to append ::text or ::attr(href) if you want the text of the links or the href attribute respectively. Similarly with XPath, you will need to append /text() or /@href to the selector to get the same.
>>> adv.crawl(
... "https://advertools.readthedocs.io/en/master/advertools.spider.html",
... "output_file.jl",
... css_selectors={
... "sidebar_links": ".toctree-l1 .internal::text",
... "sidebar_links_url": ".toctree-l1 .internal::attr(href)",
... },
... )
Or, instead of css_selectors you can add a similar dictionary for the
xpath_selectors argument:
>>> adv.crawl(
... "https://advertools.readthedocs.io/en/master/advertools.spider.html",
... "output_file.jl",
... xpath_selectors={
... "sidebar_links": '//*[contains(concat( " ", @class, " " ), concat( " ", "toctree-l1", " " ))]//*[contains(concat( " ", @class, " " ), concat( " ", "internal", " " ))]/text()',
... "sidebar_links_url": '//*[contains(concat( " ", @class, " " ), concat( " ", "toctree-l1", " " ))]//*[contains(concat( " ", @class, " " ), concat( " ", "internal", " " ))]/@href',
... },
... )
Customizing the Crawling Behavior while Following Links
If you set follow_links=True you might want to restrict this option for a
more customized crawl. This means you can decide whether to include or exclude
certain links based on certain conditions based on URL parameters and/or URL
regex patterns.
URL Query Parameters
Two options are available for this:
1. exclude_url_params: By providing a list of URL parameters, any link that
contains any of the parameters will not be followed. For example if you set
this option to ['price', 'country'], and the page currently being crawled
contains three links:
/shoes/model_a?price=10&country=us: Contains both parameters, will not be followed.
/shoes/model_a?price=10: Contains one of the parameters, will not be followed.
/shoes/model_b?color=black: Contains "color" which was not listed, will be followed
To make this efficient, and in case you want to skip all links that contain any
parameter, you can set this option to True, and any link that contains any
URL parameter will not be followed exclude_url_params=True
2. include_url_params: Similarly, you can choose the parameters that links
should contain in order for them to be followed. If a link contains any of the
listed parameters, that link will be followed. Even though this option is
straightforward, it might give you unexpected results. If you set the
parameters to include as ['price'] for example, and you start crawling from a
page that doesn't have any link containing that parameter, crawling will stop.
Yet, the website might have many links with that parameter. Please keep this in
mind, and remember that reasoning about the exclude option is easier than the
include option for this reason/example.
URL Regex Patterns
You might want even more granular control over which links to follow, and might be interested in other URL properties than their query parameters. You have two simple options to include/exclude links based on whether they match a certain regex pattern.
1. exclude_url_regex: Enter a regex, and the links will be checked if they
match it. If they do, they will not be followed, if not they will.
2. include_url_regex: This is similar but tells the crawler which links to
follow, based on whether or not they match the regex. This option also has the
same potentially tricky behavior like the include_url_params option.
Here is a simple example showing how you might control following links using all four options:
import advertools as adv
adv.crawl('https://example.com', 'output_file.jl', follow_links=True,
# don't follow links containing any of these parameters:
exclude_url_params=['price', 'region'],
# follow links containing any of these parameters:
include_url_params=['source'],
# don't follow links that contain the pattern "/fr/" or "/de/":
exclude_url_regex='/fr/|/de/',
# follow links that contain the pattern "/shop/":
include_url_regex='/shop/'
)
Spider Custom Settings and Additional Functionality
In addition to what you can control regarding the items you can extract, you can also customize the behaviour of the spider and set rules for crawling so you can control it even further.
This is provided by the custom_settings parameter. It is optional, and
takes a dictionary of settings and their values. Scrapy provides a very large
number of settings, and they are all available through this parameter
(assuming some conditions for some of the settings).
Here are some examples that you might find interesting:
CONCURRENT_REQUESTS_PER_DOMAIN Defaults to 8, and controls the number of simultaneous requests to be performed for each domain. You might want to lower this if you don't want to put too much pressure on the website's server, and you probably don't want to get blocked!
DEFAULT_REQUEST_HEADERS You can change this if you need to.
DEPTH_LIMIT How deep your crawl will be allowed. The default has no limit.
DOWNLOAD_DELAY Similar to the first option. Controls the amount of time in seconds for the crawler to wait between consecutive pages of the same website. It can also take fractions of a second (0.4, 0.75, etc.)
LOG_FILE If you want to save your crawl logs to a file, which is strongly recommended, you can provide a path to it here.
USER_AGENT If you want to identify yourself differently while crawling. This is affected by the robots.txt rules, so you would be potentially allowed/disallowed from certain pages based on your user-agent.
CLOSESPIDER_ERRORCOUNT, CLOSESPIDER_ITEMCOUNT, CLOSESPIDER_PAGECOUNT, CLOSESPIDER_TIMEOUT Stop crawling after that many errors, items, pages, or seconds. These can be very useful to limit your crawling in certain cases. I particularly like to use CLOSESPIDER_PAGECOUNT when exploring a new website, and also to make sure that my selectors are working as expected. So for your first few crawls you might set this to five hundred for example and explore the crawled pages. Then when you are confident things are working fine, you can remove this restriction. CLOSESPIDER_ERRORCOUNT can also be very useful while exploring, just in case you get unexpected errors.
The next page contains a number of strategies and recipes for crawling with code examples and explanations.
Usage
A very simple dictionary to be added to your function call:
>>> adv.crawl(
... "http://exmaple.com",
... "outpuf_file.jl",
... custom_settings={
... "CLOSESPIDER_PAGECOUNT": 100,
... "CONCURRENT_REQUESTS_PER_DOMAIN": 1,
... "USER_AGENT": "custom-user-agent",
... },
... )
Please refer to the spider settings documentation for the full details.
- crawl(url_list, output_file, follow_links=False, allowed_domains=None, exclude_url_params=None, include_url_params=None, exclude_url_regex=None, include_url_regex=None, css_selectors=None, xpath_selectors=None, custom_settings=None)[source]
Crawl a website or a list of URLs based on the supplied options.
- Parameters:
url_list (url, list) -- One or more URLs to crawl. If
follow_linksis True, the crawler will start with these URLs and follow all links on pages recursively.output_file (str) -- The path to the output of the crawl. Jsonlines only is supported to allow for dynamic values. Make sure your file ends with ".jl", e.g. output_file.jl.
follow_links (bool) -- Defaults to False. Whether or not to follow links on crawled pages.
exclude_url_params (list, bool) -- A list of URL parameters to exclude while following links. If a link contains any of those parameters, don't follow it. Setting it to
Truewill exclude links containing any parameter.include_url_params (list) -- A list of URL parameters to include while following links. If a link contains any of those parameters, follow it. Having the same parmeters to include and exclude raises an error.
exclude_url_regex (str) -- A regular expression of a URL pattern to exclude while following links. If a link matches the regex don't follow it.
include_url_regex (str) -- A regular expression of a URL pattern to include while following links. If a link matches the regex follow it.
css_selectors (dict) -- A dictionary mapping names to CSS selectors. The names will become column headers, and the selectors will be used to extract the required data/content.
xpath_selectors (dict) -- A dictionary mapping names to XPath selectors. The names will become column headers, and the selectors will be used to extract the required data/content.
custom_settings (dict) -- A dictionary of optional custom settings that you might want to add to the spider's functionality. There are over 170 settings for all kinds of options. For details please refer to the spider settings documentation.
allowed_domains (list) -- A list of the allowed domains to crawl. This ensures that the crawler does not attempt to crawl the whole web. If not specified, it defaults to the domains of the URLs provided in
url_listand all their sub-domains. You can also specify a list of sub-domains, if you want to only crawl those.
Examples
Crawl a website and let the crawler discover as many pages as available
>>> import advertools as adv >>> adv.crawl("http://example.com", "output_file.jl", follow_links=True) >>> import pandas as pd >>> crawl_df = pd.read_json("output_file.jl", lines=True)
Crawl a known set of pages (on a single or multiple sites) without following links (just crawl the specified pages) or "list mode":
>>> adv.crawl( ... [ ... "http://exmaple.com/product", ... "http://exmaple.com/product2", ... "https://anotherexample.com", ... "https://anotherexmaple.com/hello", ... ], ... "output_file.jl", ... follow_links=False, ... )
Crawl a website, and in addition to standard SEO elements, also get the required CSS selectors. Here we will get three additional columns price, author, and author_url. Note that you need to specify if you want the text attribute or the href attribute if you are working with links (and all other selectors).
>>> adv.crawl( ... "http://example.com", ... "output_file.jl", ... css_selectors={ ... "price": ".a-color-price::text", ... "author": ".contributorNameID::text", ... "author_url": ".contributorNameID::attr(href)", ... }, ... )