How to contribute

Submitting changes

Due to confidentiality issues, we are not able for now to publish any source- controlled repository (even if we do have a Mercurial repository for the project). However, this does not prevent motivated users from contributing to the project by sending patches applied to the last published version of the library. To compensate the absence of source repository, we try to update the library as often as we can in order to keep the public source archive version as close as possible to the internal development version.

Coding guidelines

In general, we try to follow the standard Python coding guidelines, which cover all the important coding aspects (docstrings, comments, naming conventions, import statements, ...) as described here:

• Style Guide for Python Code

The easiest way to check that your code is following those guidelines is to run pylint (a note greater than 8/10 seems to be a reasonnable goal).

PyQt v4.4 compatibility issues

The project has to be compatible with PyQt >= v4.4 which means that the following recommendations should be followed:

• avoid using super: when writing classes deriving from a QObject child class (i.e. almost any single class imported from QtGui or QtCore), the super builtin-function should not be used outside the constructor method (call the parent class method directly instead)
• before using any function or method from PyQt4, please check that the feature you are about to use was already implemented in PyQt4 v4.4 (more precisely in the Qt version used in PyQt4 v4.4) – if not, a workaround should be implemented to avoid breaking compatibility
• do not use the PyQt-specific QFileDialog static methods (not present in Qt) which were introduced in PyQt v4.6: getOpenFileNameAndFilter, getOpenFileNamesAndFilter and getSaveFileNameAndFilter (guidata provides wrappers around QFileDialog static methods handling the selected filter which were taken from the spyderlib library (from module spyderlib.qt.compat): they are available in guidata.qt.compat)

PyQt / PySide compatibility

In the near future, the project will be officially compatible with both PyQt and PySide.

In its current implementation, it has to be compatible with PyQt API #1 (old PyQt versions) and API #2 (PySide-compatible API, PyQt >= v4.6), which means that the following recommendations should be followed:

• QVariant objects must not be used (API #2 compatibility)
• QString and QStringList objects must not be used (API #2 compatibility)
• When connecting built-in C++ signals which were originally made to pass strings (or string lists), the arguments should always be assumed to be QString (or QStringList) objects (API #1 compatibility) and so be converted systematically to the Python equivalent object, i.e. unicode (or list).