On the command-line#
Introduction#
Trafilatura offers a robust command-line interface and can be conveniently used without writing code. Learn how to perform various tasks and leverage the full power of the tool from the terminal.
For the very first steps please refer to this multilingual, step-by-step Introduction to the command-line interface and this section of the Introduction to Cultural Analytics & Python.
For instructions related to specific platforms see:
Comment Prompt (tutorial for Windows systems)
As well as these compendia:
Introduction to the Bash Command Line (The Programming Historian)
Basic Bash Command Line Tips You Should Know (freeCodeCamp)
Quickstart#
URLs can be used directly (-u/--URL
):
# outputs main content and comments as plain text ...
$ trafilatura -u "https://github.blog/2019-03-29-leader-spotlight-erin-spiceland/"
# outputs main text with basic XML structure ...
$ trafilatura --xml --URL "https://github.blog/2019-03-29-leader-spotlight-erin-spiceland/"
# displays help message
$ trafilatura -h
You can also pipe a HTML document (and response body) to trafilatura:
# use the contents of an already existing file
$ cat myfile.html | trafilatura
# alternative syntax
$ < myfile.html trafilatura
# use a custom download utility and pipe it to trafilatura
$ wget -qO- "https://de.creativecommons.org/index.php/was-ist-cc/" | trafilatura
Extraction parameters#
Choice of HTML elements#
Several elements can be included or discarded (see list of options below):
Text elements: comments, tables
Structural elements: formatting, images, links
Only comments and text extracted from HTML <table>
elements are extracted by default, --no-comments
and --no-tables
deactivate this setting.
Further options:
--formatting
Keep structural elements related to formatting (
<b>
/<strong>
,<i>
/<emph>
etc.)--links
Keep link targets (in
href="..."
), converting relative URLs to absolute where possible--images
Keep track of images along with their targets (
<img>
attributes: alt, src, title)
Note
Certain elements are only visible in the output if the chosen format allows it (e.g. images and XML).
Including extra elements works best with conversion to XML/XML-TEI. If the output is buggy removing a constraint (e.g. formatting) can greatly improve the result.
Output format#
Output as TXT without metadata is the default, another format can be selected in two different ways:
--csv
,--json
,--xml
or--xmltei
-out
or--output-format
{txt,csv,json,xml,xmltei}
Hint
Combining TXT, CSV and JSON formats with certain structural elements (e.g. formatting or links) triggers output in TXT+Markdown format.
Optimizing for precision and recall#
The arguments --precision
& --recall
can be passed to the extractor.
They slightly affect processing and volume of textual output, respectively concerning precision/accuracy (i.e. more selective extraction, yielding less and more central elements) and recall (i.e. more opportunistic extraction, taking more elements into account).
Language identification#
Passing the argument --target-language
along with a 2-letter code (ISO 639-1) will trigger language filtering of the output if the identification component has been installed and if the target language is available.
Note
Additional components are required: pip install trafilatura[all]
Changing default settings#
Process files locally#
In case web pages have already been downloaded and stored, it is possible to process single files or directories as a whole. It can be especially helpful to separate download and extraction to circumvent blocking mechanisms, either by scrambling IPs used to access the pages or by using web browser automation software to bypass issues related to cookies and paywalls.
Trafilatura will work as well provided web pages (HTML documents) are used as input. Two major command line arguments are necessary:
--input-dir
to select a directory to read files from-o
or--output-dir
to define a directory to eventually store the results
Note
In case no directory is selected, results are printed to standard output (STDOUT, e.g. in the terminal window).
Process a list of links#
Note
Beware that there should be a tacit scraping etiquette and that a server may block you after the download of a certain number of pages from the same website/domain in a short period of time.
In addition, some websites may block the requests
user-agent. Thus, trafilatura waits a few seconds per default between requests.
For more information see the page on downloads.
Two major command line arguments are necessary here:
-i
or--input-file
to select an input list to read links from.This option allows for bulk download and processing of a list of URLs from a file listing one link per line. The input list will be read sequentially, only lines beginning with a valid URL will be read, the file can thus contain other information which will be discarded.
-o
or--output-dir
to define a directory to eventually store the results.The output directory can be created on demand, but it must be writable.
$ trafilatura -i list.txt -o txtfiles/ # output as raw text
$ trafilatura --xml -i list.txt -o xmlfiles/ # output in XML format
Hint
Backup of HTML sources can be useful for archival and further processing:
$ trafilatura --input-file links.txt --output-dir converted/ --backup-dir html-sources/ --xml
Internet Archive#
Using the option --archived
will trigger queries to the Internet Archive for web pages which could not be downloaded.
There is a fair chance to find archived versions for larger websites, whereas pages of lesser-known websites may not have been preserved there. The retrieval process is slow as it depends on a single web portal only, it is best performed for a relatively small number of URLs.
Link discovery#
Link discovery can be performed over web feeds (Atom and RSS) or sitemaps.
Both homepages and particular sitemaps or feed URLs can be used as input.
The --list
option is useful to list URLs prior to processing. This option can be combined with an input file (-i
) containing a list of sources which will then be processed in parallel.
For more information please refer to the tutorial on content discovery.
Feeds#
# automatically detecting feeds starting from the homepage
$ trafilatura --feed "https://www.dwds.de/" --list
# already known feed
$ trafilatura --feed "https://www.dwds.de/api/feed/themenglossar/Corona" --list
# processing a list in parallel
$ trafilatura -i mylist.txt --feed --list
Youtube tutorial: Extracting links from web feeds
Sitemaps#
# run link discovery through a sitemap for sitemaps.org and store the resulting links in a file
$ trafilatura --sitemap "https://www.sitemaps.org/" --list > mylinks.txt
# using an already known sitemap URL
$ trafilatura --sitemap "https://www.sitemaps.org/sitemap.xml" --list
# targeting webpages in German
$ trafilatura --sitemap "https://www.sitemaps.org/" --list --target-language "de"
For more information on sitemap use and filters for lists of links see this blog post: Using sitemaps to crawl websites.
Youtube tutorial: Listing all website contents with sitemaps
URL inspection prior to download and processing#
$ trafilatura --sitemap "https://www.sitemaps.org/" --list --url-filter "https://www.sitemaps.org/de"
$ trafilatura --sitemap "https://www.sitemaps.org/" --list --url-filter "protocol"
Using a subpart of the site also acts like a filter, for example --sitemap "https://www.sitemaps.org/de/"
.
For more information on sitemap use and filters for lists of links see this blog post: Using sitemaps to crawl websites and this tutorial on link filtering.
Further information#
Hint
See also how to modify the default settings.
For all usage instructions see trafilatura -h
:
trafilatura [-h] [-i INPUTFILE | --input-dir INPUTDIR | -u URL]
[--parallel PARALLEL] [-b BLACKLIST] [--list]
[-o OUTPUTDIR] [--backup-dir BACKUP_DIR] [--keep-dirs]
[--hash-as-name] [--feed [FEED] | --sitemap [SITEMAP] |
--crawl [CRAWL] | --explore [EXPLORE]] [--archived]
[--url-filter URL_FILTER [URL_FILTER ...]] [-f]
[--formatting] [--links] [--images] [--no-comments]
[--no-tables] [--only-with-metadata]
[--target-language TARGET_LANGUAGE] [--deduplicate]
[--config-file CONFIG_FILE]
[-out {txt,csv,json,xml,xmltei} | --csv | --json | --xml | --xmltei]
[--validate-tei] [-v] [--version]
Command-line interface for Trafilatura
- optional arguments:
- -h, --help
show this help message and exit
- -v, --verbose
increase logging verbosity (-v or -vv)
- --version
show version information and exit
- Input:
URLs, files or directories to process
- -i INPUTFILE, --input-file INPUTFILE
name of input file for batch processing
- --input-dir INPUTDIR
read files from a specified directory (relative path)
- -u URL, --URL URL
custom URL download
- --parallel PARALLEL
specify a number of cores/threads for downloads and/or processing
- -b BLACKLIST, --blacklist BLACKLIST
file containing unwanted URLs to discard during processing
- Output:
Determines if and how files will be written
- --list
display a list of URLs without downloading them
- -o OUTPUTDIR, --output-dir OUTPUTDIR
write results in a specified directory (relative path)
- --backup-dir BACKUP_DIR
preserve a copy of downloaded files in a backup directory
- --keep-dirs
keep input directory structure and file names
- --hash-as-name
use hash value as output file name instead of random default
- Navigation:
Link discovery and web crawling
- --feed URL
look for feeds and/or pass a feed URL as input
- --sitemap URL
look for sitemaps for the given website and/or enter a sitemap URL
- --crawl URL
crawl a fixed number of pages within a website starting from the given URL
- --explore URL
explore the given websites (combination of sitemap and crawl)
- --archived
try to fetch URLs from the Internet Archive if downloads fail
- --url-filter URL_FILTER
only process/output URLs containing these patterns (space-separated strings)
- Extraction:
Customization of text and metadata processing
- -f, --fast
fast (without fallback detection)
- --formatting
include text formatting (bold, italic, etc.)
- --links
include links along with their targets (experimental)
- --images
include image sources in output (experimental)
- --no-comments
don’t output any comments
- --no-tables
don’t output any table elements
- --only-with-metadata
only output those documents with title, URL and date (for formats supporting metadata)
- --target-language TARGET_LANGUAGE
select a target language (ISO 639-1 codes)
- --deduplicate
filter out duplicate documents and sections
- --config-file CONFIG_FILE
override standard extraction parameters with a custom config file
- --precision
favor extraction precision (less noise, possibly less text)
- --recall
favor extraction recall (more text, possibly more noise)
- Format:
Selection of the output format
- -out, --output-format
determine output format, possible choices: txt, csv, json, xml, xmltei
- --csv
CSV output
- --json
JSON output
- --xml
XML output
- --xmltei
XML TEI output
- --validate-tei
validate XML TEI output