Python Bindings

Python in gnucash has two main aspects:

• Python bindings
• Python shell

Python bindings provide SWIG wrapper functions for some of gnucashs C/C++ API. They can be used to write standalone scripts to work with the gnucash financial data. In the source tree they are located at bindings/python.

The python shell on the other hand (if enabled) opens at gnucash startup and provides a python environment to use with the running gnucash instance. In the source tree it is located at gnucash/python. The python bindings can be used in this shell. Be careful: gnucash is not designed to have multiple instances manipulating the data at the same time, reading should be secure.

Note, that there is also a pure python client, piecash, to read and manipulate GnuCash books if saved in of the three SQL backends (sqlite, MySQL, Postgres). Currently (Oct 2020), piecash supports files created up to GnuCash 4.2.

General notice

Python bindings have been added to gnucash in 2008 or earlier. There is still very little documentation and probably few people would know how to use it. While not a manual, this page was created in the hope to provide information for those interested in gnucash and python.

See also

• http://article.gmane.org/gmane.comp.gnome.apps.gnucash.devel/23800 "Re: documentation for python bindings" and
• http://article.gmane.org/gmane.comp.gnome.apps.gnucash.devel/23613 "Re: documentation for python bindings" with some pointers on how to look up the existing documentation
• Perhaps it was this thread: documentation for python bindings

Setting things up

Requirements

Gnucash 5.x requires Python 3.6.

GnuCash's Python bindings has been known to work with CPython version 3.2 or later as of GnuCash 3.0.

Linux

Ubuntu/Debian

The easiest way to install the GnuCash Python bindings is via apt-get:

sudo apt-get install python3-gnucash

Archlinux

The python bindings are install with the gnucash package.

Other Linux distributions / GnuCash from source

To configure with Python

cmake -DWITH_PYTHON=ON -DCMAKE_INSTALL_PREFIX=/opt/gnc/git/

I use https://en.wikipedia.org/wiki/IPython IPython for an interactive shell. If you prefer something else, let us know if there is any difference.

export PYTHONPATH=$PYTHONPATH:/opt/gnc/git/lib/python{{Python_Version}}/site-packages

This adds the gnucash python bindings to your PYTHONPATH assuming that your gnucash resides in /opt/gnc/git/. Notice that if even if you install to the default CMAKE_INSTALL_PREFIX of /usr/local, the Ubuntu/Debian python is compiled to search for packages in dist-packages and does not find them in site-packages.

You can then either start up an interactive python session with ipython or call your script to be executed:

gnucash-env ipython
gnucash-env python /path/to/script

Notes

To install ipython run

sudo pip ipython

pip is the package installer for Python.

Mac OSX

Install GnuCash via MacPorts:

sudo port install gnucash +python{{Python_Version_short}}

Note: at the time of writing, only the non-quartz environment is supported.

Setup the PYTHONPATH to point to your macports install:

export PYTHONPATH=$PYTHONPATH:/opt/local/lib/python{{Python_Version}}/site-packages

You can then either start up an interactive python session with ipython or call your script to be executed:

ipython
python /path/to/script

Documentation

As pointed out in the introductory paragraph, the documentation is rather slim at this point in time. Below you will find some sources where you might be able to find what you are looking for. Generally speaking, this is not yet end-user friendly stuff.

Principles

Python bindings provide SWIG wrapper functions for some of gnucashs C/C++ API. They can be used to write standalone scripts to work with the gnucash financial data.

What SWIG does

• see Doxygen - python-bindings (bugfix branch)

How to use the Python bindings

• see Doxygen - python-bindings (bugfix branch)

Further Docs

Doxygen

Have a look at the python-bindings (bugfix branch) or python-bindings (feature branch) in the doxygen API documentation.

• business functions documentation
• Example scripts

Github

The source code of gnucash including the python bindings can be accessed on github.

• Example scripts from the source code.

Inside python

Using python or ipython there is some sparse help:

big long list of stuff

 import gnucash.gnucash_core_c
 help(gnucash.gnucash_core_c)
 dir(gnucash.gnucash_core_c)

higher abstraction level help

 import gnucash.gnucash_core
 import gnucash.gnucash_business
 help(gnucash.gnucash_core)
 help(gnucash.gnucash_business)

Mailing list

Again, http://article.gmane.org/gmane.comp.gnome.apps.gnucash.devel/23613 contained some more hopefully useful pointers, but the page is no longer available.

Example Usages

This section should contain some pointers to scripts using the GnuCash Python bindings:

• https://github.com/hjacobs/gnucash-qif-import --- imports transactions from QIF text files into GnuCash's own file format
• https://github.com/hjacobs/gnucash-stock-portfolio --- script using the GnuCash commodity/price table
• https://github.com/hjacobs/gnucash-fiximports --- tries to fix target accounts using regular expression rules (e.g. PIZZA -> Expenses:Dining)

Important

GnuCash uses DeprecationWarnings, which are disabled by default in Python. Be sure to test periodically with python -Wd or with PYTHONWARNINGS=default set in the environment so that you know about API that will disappear in the next major release. See Development_Process#LibGnuCash API Stability for the policy.

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