milgen / qgis2to3

Tools to help porting QGIS Plugins from api version 2 to api version 3

This repository includes two tools to help you migrate your QGIS 2 plugins to QGIS 3: qgis2to3 and qgis2apifinder. Both tools are distributed as a Python package installable via pip.

Blog post

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/

Description

qgis2to3

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.

qgis2apifinder

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.

install

pip install qgis2to3

Please note that often for system-wide installation you need sudo.

Usage

qgis2to3

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

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