DO NOT USE THIS CODE.
The index this code uses is broken, see https://github.com/trivio/common_crawl_index/issues/13
A new index has been created, see https://github.com/ikreymer/cdx-index-client for more information.
commoncrawlindex
Common Crawl is an open repository of web crawl data that can be accessed and analyzed by everyone.
commoncrawlindex is a simple Python interface to the Common Crawl URL Index and the Common Crawl dataset.
This is a pretty significant fork of trivio/common_crawl_index, created with the goal of being easier to use.
Installation
From github:
$ git clone git@github.com:wiseman/common_crawl_index.git
$ cd common_crawl_index
$ python setup.py install
Using pip:
$ pip install commoncrawlindex
Usage
You can use commoncrawlindex to find URLs that are in the Common Crawl dataset and you can use it to fetch the stored contents of those URLs.
Looking up URLs
Searching the index is done with cci_lookup. You give it a URL
prefix on the command line and it will write every matching URL in the
index to stdout:
$ cci_lookup com.metafilter # Find every URL at metafilter.com
com.metafilter.ask/100000/Ideas-for-pureed-food-for-a-30something-who-is-really-picky:http
com.metafilter.ask/100014/How-to-care-for-my-geek-husband:http
com.metafilter.ask/100020/How-can-I-investigateremedy-possibly-misleading-loan-agreements-from-several-years-ago:http
com.metafilter.ask/100033/Whats-the-best-way-to-react-to-a-socially-awkward-situation:http
[...and so on for about 120000 URLs.]
Note that the URL index contains reversed domains and has the protocol
last, and you query by giving cci_lookup a reversed URL prefix.
URLs are returned in lexicographic order.
Here's an example of a more specifix query that finds all URLs from the projects.metafilter.com sub-site:
$ cci_lookup com.metafilter.projects
com.metafilter.projects/1029/bunt-cake-a-webcomic-thing:http
com.metafilter.projects/1030/Question-Party:http
com.metafilter.projects/1041/Free-magazines-on-your-iPhone:http
[...etc. for a total of about 250 URLs.]
Even more specific, finding URLs of projects posts whose IDs begin with 3:
$ cci_lookup com.metafilter.projects/3
com.metafilter.projects/3012/You-are-listening-to-Los-Angeles:http
com.metafilter.projects/3031/RetCon-Artists-Improving-the-Future-by-Improving-the-Past:http
com.metafilter.projects/3042/GLTICH-Karaoke:http
[etc.]
Metadata
You can also display the metadata associated with each URL:
$ cci_lookup --print_metadata com.metafilter.projects/3
com.metafilter.projects/3012/You-are-listening-to-Los-Angeles:http {"compressedSize": 7702, "arcSourceSegmentId": 1346876860782, "arcFilePartition": 4245, "arcFileDate": 1346908921144, "arcFileOffset": 1850172}
com.metafilter.projects/3031/RetCon-Artists-Improving-the-Future-by-Improving-the-Past:http {"compressedSize": 6464, "arcSourceSegmentId": 1346876860782, "arcFilePartition": 4245, "arcFileDate": 1346908597590, "arcFileOffset": 93006430}
com.metafilter.projects/3042/GLTICH-Karaoke:http {"compressedSize": 6015, "arcSourceSegmentId": 1346876860782, "arcFilePartition": 3331, "arcFileDate": 1346908329648, "arcFileOffset": 88640475}
[etc.]
Metadata is in JSON format and is separated from the URL by a tab character. Say you want to use Hadoop to process common crawl data for a single site. You don't need to process every source segment, but which ones do you need? Here's one way to find out (using jq):
$ cci_lookup --print_metadata com.metafilter |
awk -F '\t' '{print $2;}' |
jq '.arcSourceSegmentId' |
sort |
uniq -c |
sort -rn
21439 1346876860765
20182 1346876860838
18223 1346876860840
13568 1346876860819
8843 1346876860614
8717 1346876860807
6748 1346876860877
6580 1346876860817
3822 1346823846176
1662 1346876860782
1480 1346876860648
1476 1346876860609
1055 1346876860804
979 1346876860843
935 1346876860798
912 1346876860493
633 1346823845675
537 1346876860454
409 1346876860795
296 1346876860567
232 1346876860828
226 1346876860445
44 1346823846125
42 1346823846039
2 1346876860779
2 1346876860777
1 1346876860774
1 1346876860611
1 1346823846150
That's 29 different segments, which is only about half of the 58 total valid segments.
Fetching URLs
You can fetch URLs from the Common Crawl dataset using cci_fetch.
You give it a specific URL or URL prefix and it will fetch the saved
pages and write them to stdout:
# cci_fetch 'com.metafilter.projects/3012/You-are-listening-to-Los-Angeles:http'
Fetching com.metafilter.projects/3012/You-are-listening-to-Los-Angeles:http
http://projects.metafilter.com/3012/You-are-listening-to-Los-Angeles 50.22.177.14 20120516211439 text/html 31096
HTTP/1.1 200 OK
Date:Wed, 16 May 2012 21:14:36 GMT
Server:Apache
Vary:Accept-Encoding
Connection:close
Transfer-Encoding:chunked
Content-Type:text/html; charset=UTF-8
Content-Encoding:gzip
x-commoncrawl-DetectedCharset:UTF-8
<a name="content"></a>
<div id="page">
<div id="right" style="margin:0;padding:0;float:right;width:145px;">
[etc.]
(Note that the page saved in the Common Crawl dataset includes HTTP headers.)
If you're fetching lots of pages, you can save them in individual files. Here's how you would download every page the dataset has from metafilter.com:
$ cci_fetch --output_to_file com.metafilter
Fetching com.metafilter.ask/100000/Ideas-for-pureed-food-for-a-30something-who-is-really-picky:http
Fetching com.metafilter.ask/100014/How-to-care-for-my-geek-husband:http
Fetching com.metafilter.ask/100020/How-can-I-investigateremedy-possibly-misleading-loan-agreements-from-several-years-ago:http
[etc.]
If you're downloading lots of data, you may want to keep it in its compressed (gzipped) format:
$ cci_fetch --compress --output_to_file com.metafilter
If you're wondering how much disk space this will use, you can check the metadata and sum the compressed size of every file:
$ cci_lookup --print_metadata com.metafilter |
awk -F '\t' '{print $2;}' |
jq '.compressedSize' |
awk '{sum+=$1;} END {print sum;}'
1252326930
It's a little more than 1 GB in compressed form, which isn't too not bad.
To speed up the download you can use multiple processes. Here's how
to download everything to individual gzipped files using 20 parallel
cci_fetch processes:
$ cci_lookup com.metafilter | xargs -d '\n' -n 100 -P 20 cci_fetch -C -O
