This repository includes two tools to help you migrate your QGIS 2 plugins
to QGIS 3:
qgis2apifinder. Both tools are distributed as a
Python package installable via pip.
there is a nice write-up on how to use this tools at http://www.opengis.ch/2018/04/13/porting-qgis-plugins-to-api-v3-strategy-and-tools/
The codeporting package is a copy of the files found in https://github.com/qgis/QGIS/tree/master/scripts to allow for quick downloading and simple installation without the need of downloading the whole QGIS repository. This is a set of fixers for the python 2to3 command that will update your Python 2 code to Python 3. The additional fixers will also take care of the PyQt4 to PyQt5 porting as well as some other things.
The api2finder package is a tool that helps you find usages of the QGIS API version 2 and proposes changes to API version 3
it is based on a machine parsing of https://qgis.org/api/api_break.html so the results are as good as the information there. Also, being a simple parser, it just gives a hint where to look at. It is by no means a complete tool to find all the possible API incompatibility.
Methods are matched just based on their names and not on their classes, so there might be various false positives. Also, the same keyword might have been edited in various classes, api2finder will show you all the suggestion for that keyword.
pip install qgis2to3
Please note that often for system-wide installation you need sudo.
Usage: qgis2to3 [options] file|dir ... Options: -h, --help show this help message and exit -d, --doctests_only Fix up doctests only -f FIX, --fix=FIX Each FIX specifies a transformation; default: all -j PROCESSES, --processes=PROCESSES Run 2to3 concurrently -x NOFIX, --nofix=NOFIX Prevent a transformation from being run -l, --list-fixes List available transformations -p, --print-function Modify the grammar so that print() is a function -v, --verbose More verbose logging --no-diffs Don't show diffs of the refactoring -w, --write Write back modified files -n, --nobackups Don't write backups for modified files -o OUTPUT_DIR, --output-dir=OUTPUT_DIR Put output files in this directory instead of overwriting the input files. Requires -n. -W, --write-unchanged-files Also write files even if no changes were required (useful with --output-dir); implies -w. --add-suffix=ADD_SUFFIX Append this string to all output filenames. Requires -n if non-empty. ex: --add-suffix='3' will generate .py3 files.
qgis2apifinder [-h] [-s] [-a] [-n] path Find usages of the QGIS api version 2 and propose changes for api version 3 positional arguments: path File or directory to be analysed optional arguments: -h, --help show this help message and exit -s, --summarize Show only the summaries for each analysed file -a, --all Include very frequent words like ['layout', 'layer', 'fields'] in the analysis -n, --nonote Do not show the note about false positives