• Project Goals
• Getting Started
  • Prerequisites
  • Usage
  • Customization
• Converting
• Project Information
  • Built With
  • Contributing
  • Versioning
  • Authors
  • License
  • Acknowledgments

An automatic Python Qt binding transpiler to the Qt.py abstraction layer. It aims to help in your modernization of your Python Qt code. QtPyConvert supports the following bindings out of the box:

• PyQt4
• PySide
• PyQt5
• PySide2

It also has experimental support for defining your own bindings.

_{See customization for more information}

Convert any code using any of the four major Qt for Python bindings into the standardized Qt.py abstraction layer.

Warn users about incompatibilities or unsupported code. (WIP)

Standardize Qt imports to maintain sanity in code comprehension.

_{Removing start imports and deep class/module imports}

When using QtPyConvert, developers should be aware of any shortcomings of Qt.py or its subset of supported features.

Basically read the README in the Qt.py project and be aware of what it does and does not do.

QtPyConvert reads the private values of the Qt.py project to build it's internal conversion processes. To install this run

pip install Qt.py

QtPyConvert also uses RedBaron as an alternate abstract syntax tree. Redbaron allows us to modify the source code and write it back out again, preserving all comments and formatting.

pip install redbaron

We also provide a requirements.txt file which you could install instead by...

pip install -r requirements.txt

You should also have access to any of your source bindings so that Qy.py can import them freely.

A full list of dependencies is as follows:

• rebaron
• baron
• rply
• appdirs
• qt_py
• argparse

$ qt_py_convert [-h] [-r] [--stdout] [--write-path WRITE_PATH] [--backup]
                [--show-lines] [--to-method-support] [--explicit-signals-flag]
                files_or_directories [files_or_directories ...]

QtPyConvert supports some custom bindings if you are willing to do a little bit of work.

This is done through environment variables:

Note This feature is experimental and has only been used internally a few times. Support for this feature will probably be slower than support for the core functionality of QyPyConvert.

QtPyConvert is still a bit of a work in progress, there are things that it cannot yet convert with 100% certainty.
The following is a guide of common problems that you might have pop up.

The most common thing that you will probably see is a Baron parsing error.

Traceback (most recent call last):
  File "/usr/bin/qt_py_convert", line 47, in <module>
    main(args.file_or_directory, args.recursive, args.write)
  File "/usr/bin/qt_py_convert", line 40, in main
    process_folder(path, recursive=recursive, write=write)
  File "/usr/lib/python2.7/site-packages/qt_py_convert/run.py", line 310, in process_folder
    process_folder(os.path.join(folder, fn), recursive, write, fast_exit)
  File "/usr/lib/python2.7/site-packages/qt_py_convert/run.py", line 310, in process_folder
    process_folder(os.path.join(folder, fn), recursive, write, fast_exit)
  File "/usr/lib/python2.7/site-packages/qt_py_convert/run.py", line 310, in process_folder
    process_folder(os.path.join(folder, fn), recursive, write, fast_exit)
  File "/usr/lib/python2.7/site-packages/qt_py_convert/run.py", line 310, in process_folder
    process_folder(os.path.join(folder, fn), recursive, write, fast_exit)
  File "/usr/lib/python2.7/site-packages/qt_py_convert/run.py", line 302, in process_folder
    os.path.join(folder, fn), write=write, fast_exit=fast_exit
  File "/usr/lib/python2.7/site-packages/qt_py_convert/run.py", line 282, in process_file
    aliases, mappings, modified_code = run(source, fast_exit=fast_exit)
  File "/usr/lib/python2.7/site-packages/qt_py_convert/run.py", line 264, in run
    psep0101.process(red)
  File "/usr/lib/python2.7/site-packages/qt_py_convert/_modules/psep0101/process.py", line 215, in process
    getattr(Processes, issue)(red, psep_issues[issue]) if psep_issues[issue] else None
  File "/usr/lib/python2.7/site-packages/qt_py_convert/_modules/psep0101/process.py", line 34, in _process_qvariant
    node.parent.replace(changed)
  File "/usr/lib/python2.7/site-packages/redbaron/base_nodes.py", line 1016, in replace
    new_node = self._convert_input_to_node_object(new_node, parent=None, on_attribute=None, generic=True)
  File "/usr/lib/python2.7/site-packages/redbaron/base_nodes.py", line 156, in _convert_input_to_node_object
    return Node.from_fst(baron.parse(value)[0], parent=parent, on_attribute=on_attribute)
  File "/usr/lib/python2.7/site-packages/baron/baron.py", line 57, in parse
    to_return = _parse(tokens, print_function)
  File "/usr/lib/python2.7/site-packages/baron/baron.py", line 26, in _parse
    raise e
baron.parser.ParsingError: Error, got an unexpected token RIGHT_SQUARE_BRACKET here:
   1 self.user_data[index.row(]<---- here

The token RIGHT_SQUARE_BRACKET should be one of those: BACKQUOTE, BINARY, BINARY_RAW_STRING, BINARY_STRING, COMMA, COMPLEX, DOUBLE_STAR, FLOAT, FLOAT_EXPONANT, FLOAT_EXPONANT_COMPLEX, HEXA, INT, LAMBDA, LEFT_BRACKET, LEFT_PARENTHESIS, LEFT_SQUARE_BRACKET, LONG, MINUS, NAME, NOT, OCTA, PLUS, RAW_STRING, RIGHT_PARENTHESIS, STAR, STRING, TILDE, UNICODE_RAW_STRING, UNICODE_STRING

It is not normal that you see this error, it means that Baron has failed to parse valid Python code. It would be kind if you can extract the snippet of your code that makes Baron fail and open a bug here: https://github.com/Psycojoker/baron/issues

Sorry for the inconvenience.

Because we are using an alternate Python AST, there are sometimes issues on edge cases of code. Unfortunately, Baron get's confused sometimes when it tries to send us a helpful traceback and the error is usually earlier than it thinks.
There are two usual suspects when getting a Baron ParsingError.

This is a problem that will popup with Baron because it actually pays attention to the comments, whereas Python just throws them out. If you are getting an error similar to the above, you will want to look higher in the script for incorrectly indented comments, multiline and single line ones.

This is less common than the indented comments issue but has still shown up in a few cases for us internally.
There are times where Baron cannot parse a print statement and turning it into a print function by enclosing it in parenthesis seems to fix it.

The Qt.py module does not support uic.loadUiType.
Please see mottosso/Qt.py#237

As of Qt 4.7 QLayout.setMargin has been set to obsolete which means that it will be removed.
As it turns out, they removed it in Qt5. The obsoleted page is here

Obsoleted code

layout = QLayout()
layout.setMargin(10)

Replacement code

layout = QLayout()
layout.setContentsMargins(10, 10, 10, 10)

There are several things that we would love to have support for in QtPyConvert but we just haven't gotten around to yet for various reasons.

• Warnings about deprecated/obsoleted method calls in Qt4 code.
  • There were many method calls that were removed in Qt5 and most people were unaware that they should be using something else when they wrote the Qt4 code.
    There are lists on the Qt5 docs about what was deprecated and what the replacements are (if any) in Qt5 code. It would be nice if we could warn the user about these when we detect them and potentially automatically fix some of them too.
  • In a perfect world we would be able to dynamically build the list of these by scraping the Qt website too.
• Better support for api-v1.0 method removal. Currently we are basially looking for the method names because they are quite unique. Ideally it'd be great if we could somehow record the type of the object at least in locals and then if that object was a QString for example, see if it is using any methods that aren't on a builtin string type.
• Better support for the QtCompat..method replacements. Much of this would require the previous feature to be somewhat figured out. We would need to at least minimally track variable types.

• Qt.py - The Qt abstraction library that we port code to.
• RedBaron - The alternate Python AST which allows us to modify and preserve comments + formatting.

Please read CONTRIBUTING.md for details on our code of conduct, and the process for submitting pull requests to us.

We use semantic versioning for versioning. For the versions available, see the tags on this repository.

• Alex Hughes - Initial work - Digital Domain
• Rafe Sacks - Prototyping help - Digital Domain

See also the list of contributors who participated in this project.

This project is licensed under a modified Apache 2.0 license - see the LICENSE file for details

• The developers of Qt.py
• The developers of RedBaron
• etc