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The Reynir NLP parser for Icelandic, packaged for PyPi
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A fast, efficient natural language parser for Icelandic


Greynir is a Python 3.x package for parsing Icelandic text into sentence trees (i.e. full constituency parse trees). The trees can then be used to extract information from the text, for instance about people, titles, entities, facts, actions and opinions.

Along the way, Greynir tokenizes the text, finds lemmas and assigns part-of-speech (POS) tags to every word.

Full documentation for Greynir is available here.

Greynir is the engine of, a natural-language front end for a database of 9 million sentences parsed from Icelandic news articles, and Embla, a natural-language query app for smart phones.

Greynir uses the Tokenizer package, by the same authors, to tokenize text.


>>> from reynir import Greynir
>>> g = Greynir()
>>> sent = g.parse_single("Ása sá sól.")
>>> print(sent.tree.view)
P                               # Root
+-S-MAIN                        # Main sentence
  +-IP                          # Inflected phrase
    +-NP-SUBJ                   # Noun phrase, subject
      +-no_et_nf_kvk: 'Ása'     # Noun, singular, nominative, feminine
    +-VP                        # Verb phrase containing arguments
      +-VP                      # Verb phrase containing verb
        +-so_1_þf_et_p3: 'sá'   # Verb, 1 accusative arg, singular, 3rd p
      +-NP-OBJ                  # Noun phrase, object
        +-no_et_þf_kvk: 'sól'   # Noun, singular, accusative, feminine
+-'.'                           # Punctuation
>>> sent.tree.nouns
['Ása', 'sól']
>>> sent.tree.verbs
>>> sent.tree.flat
'P S-MAIN IP NP-SUBJ no_et_nf_kvk /NP-SUBJ VP so_1_þf_et_p3
    NP-OBJ no_et_þf_kvk /NP-OBJ /VP /IP /S-MAIN p /P'
>>> # The subject noun phrase (S.IP.NP also works)
>>> sent.tree.S.IP.NP_SUBJ.lemmas
>>> # The verb phrase
>>> sent.tree.S.IP.VP.lemmas
['sjá', 'sól']
>>> # The object within the verb phrase (S.IP.VP.NP also works)
>>> sent.tree.S.IP.VP.NP_OBJ.lemmas


This package runs on CPython 3.5 or newer, and on PyPy 3.5 or newer.

To find out which version of Python you have, enter:

$ python --version

If a binary wheel package isn't available on PyPi for your system, you may need to have the python3-dev and/or potentially python3.X-dev packages (where X is your Python sub-version, such as 6 for 3.6), or their Windows equivalents, installed on your system to set up Greynir successfully. This is because a source distribution install requires a C++ compiler and linker:

$ # Debian or Ubuntu:
$ sudo apt-get install python3-dev
$ sudo apt-get install python3.6-dev

Depending on your system, you may also need to install libffi-dev:

$ # Debian or Ubuntu
$ sudo apt-get install libffi-dev


To install this package, assuming Python 3 is your default Python:

$ pip install reynir

If you have git and git-lfs installed and want to be able to edit the source, do like so:

$ git clone
$ cd ReynirPackage
$ # [ Activate your virtualenv here if you have one ]
$ pip install -e .

The package source code is now in ReynirPackage/src/reynir.

Note that git-lfs is required to clone and pull the full compressed binary files for the Beygingarlýsing íslensks nútímamáls (BÍN) database. If it is missing, you will get assertion errors when you try to run Greynir.


To run the built-in tests, install pytest, cd to your ReynirPackage subdirectory (and optionally activate your virtualenv), then run:

$ python -m pytest


Please consult Greynir's documentation for detailed installation instructions, a quickstart guide, and reference information, as well as important information about copyright and licensing.

Copyright and licensing

Greynir is copyright (C) 2020 by Miðeind ehf. The original author of this software is Vilhjálmur Þorsteinsson.

This set of programs is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This set of programs is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

The full text of the GNU General Public License v3 is included here and also available here:

If you would like to use this software in ways that are incompatible with the standard GNU GPLv3 license, please contact Miðeind ehf. to negotiate alternative arrangements.

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