# A note about pyqt4v2¶

Starting with pytest-qt version 2.0, PyQt or PySide are lazily loaded when first needed instead of at pytest startup. This usually means pytest-qt will import PyQt or PySide when the tests actually start running, well after conftest.py files and other plugins have been imported. This can lead to some unexpected behaviour if pyqt4v2 is set.

If the conftest.py files, either directly or indirectly, set the API version to 2 and import PyQt4, one of the following cases can happen:

• if all the available types are set to version 2, then using pyqt4 or pyqt4v2 is equivalent

• if only some of the types set to version 2, using pyqt4v2 will make pytest to fail with an error similar to:

INTERNALERROR> sip.setapi("QDate", 2)
INTERNALERROR> ValueError: API 'QDate' has already been set to version 1


If this is the case, use pyqt4.

If the API is set in the test functions or in the code imported by them, then the new behaviour is indistinguishable from the old one and pyqt4v2 must be used to avoid errors if version 2 is used.