pypolibox is a database-to-text generation (NLG) software built on Python 2.7, NLTK and Nicholas FitzGerald’s pydocplanner.
Using a database of technical books and some user input, pypolibox generates sentences descriptions. These descriptions are then used by the OpenCCG surface realiser to generate written sentences in German.
In order to generate sentences (instead of abstract sentence
descriptions), you will need to install OpenCCG (tested with version
0.9.5). Make sure that you can call
tccg from the command line,
e.g. by adding the
openccg/bin directory to your
Under Linux, you’d have to add something like this to your
export PATH=/home/username/bin/openccg/bin:$PATH export OPENCCG_HOME=/home/username/bin/openccg export JAVA_HOME=/usr/lib/jvm/java-1.7.0-openjdk-amd64
Under Windows, you’ll have to set the environment variables
JAVA_HOME and add the full path of your
openccg/bin directory to the
pywin32 also needs to be installed under Windows.
Install from PyPI¶
pip install pypolibox
Under Linux, you might have to prepend that command with
execute it as root. Under Windows, you’ll need to run this command in a
console with administrator rights.
Install from source¶
You might also need superuser/admin rights for this (see above).
git clone https://github.com/arne-cl/pypolibox.git cd pypolibox python setup.py install
Command line usage¶
pypolibox can be used from the command line or from within a Python
interpreter. To see all the available options, enter:
To find books that are written in German and use the programming language Prolog, type:
pypolibox --language German --proglang Prolog
or, if you prefer short but cryptic commands:
pypolibox -l German -p Prolog
You can choose between several output formats using the
openccggenerates sentences using OpenCCG (default option)
textplan-xmlgenerates an XML representation of the textplans
textplan-featstructgenerates a feature structure representation (
hldsgenerates an HLDS XML representations of all the sentences.
In future versions, you will be able to choose between several output
natural languages the
(currently only German is supported).
The following example query will generate HLDS XML snippets describing books about Prolog written in German:
pypolibox --language German --proglang Prolog --output-format hlds
Further usage examples can be found in the
If you’d like to access
within a Python interpreter, you can simply use the same arguments.
Instead of a string like -l German -p Prolog, you will have to
provide your arguments as a list of strings:
Query(["-l", "German", "-p", "Prolog"])
This query would be equivalent to the command line queries above.
pypolibox is built as a pipeline, where each important step is
represented by a class. Each of these classes function as the input
of the next class in the pipeline, e.g.:
query = Query(["-l", "German", "-p", "Prolog"]) Results(query) Books(Results(query)) ... TextPlans(AllMessages(AllPropositions(AllFacts(Books(Results(query))))))
If you instanciate a Query with your query arguments, you can use
Query instance as the input of a
(which contains the data that the database provided for your query),
which in turn can be used as the input of a
Books instance etc.
Of course, you wouldn’t want to chain all those classes just to retrieve
textplans. To do so, simply use one of the functions provided in the
debug module, either by running the
debug.py file in
the interpreter or by importing it:
import debug debug.gen_textplans(["-l", "German", "-p", "Prolog"])
This function call would return the same results as the aforementioned
command line calls. For further testing, try
basically are lists of predefined valid and invalid query arguments and which
can be used to query the database (and see how errors are handled).
You can generate an HTML or PDF version by running these commands in
to produce a PDF (
to produce a set of HTML files (
The pypolibox package contains the following modules:
pypoliboxmodule is the main module, which is invoked from the command line.
databasemodule handles the user input, queries the database and returns the results.
factsconverts those results into attribute value matrices.
propositionsmodule evaluates those facts (positive, negative, neutral).
textplanmodule takes those propositions and turns them into messages. In contrast to propositions, messages do not contain duplicates and add comparative information. Rules will be used to combine those message into constituent sets and ultimately into one text plan. The
textplanmodule also allows exporting those text plans in XML format.
rulesmodule contains the rules used by be the
textplanmodule to combine messages into constituent sets and textplans, respectively.
messagesmodule generates messages from propositions, which will be used by the
lexicalize_messageblocksis the “main” module of the lexicalization. For each message block in a textplan, it generates one or more possible lexicalizations which are then realized by the
lexicalizationmodule generates lexicalizations (in HLDS-XML format) for each message, which are used by the
lexicalize_messageblocksmodule to form lexicalizations of complete message blocks.
- A note on terminology: A message block in
pypoliboxis basically an instance of the
Messageclass, e.g an “id” message block. This “id” message block in turn consists of several messages, e.g. an “authors” message and a “title” message.
realizationmodule takes a lexicalized phrase or sentence (in HLDS-XML format) and converts it into a surface realization (with the help of OpenCCGs
hldsmodule allows to convert textplans from a
nltk.featstruct-based format to HLDS-XML and vice versa. In addition, the module can produce attribute-value matrices of these textplans as LaTeX/PDF files.
The code is licensed under GPL Version 3. The grammar fragment is licensed under Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
Arne Neumann (original author), Pablo Duboue
This software reimplements parts of the Java-based JPolibox text-generation software written by Alexandra Strelakova, Felix Dombek, Mathias Langer and Till Kolter. pypolibox also includes a heavily modified version of Nicholas FitzGerald’s pydocplanner, which he released under a Creative Commons license (not specified further). The German OpenCCG grammar fragment that comes with pypolibox was written by Martin Oltmann.