pyqtgraph/examples/test_examples.py

from __future__ import print_function, division, absolute_import
from pyqtgraph import Qt
from . import utils
import itertools
import pytest
import os, sys


# printing on travis ci frequently leads to "interrupted system call" errors.
# as a workaround, we overwrite the built-in print function (bleh)
if os.getenv('TRAVIS') is not None:
    if sys.version_info[0] < 3:
        import __builtin__ as builtins
    else:
        import builtins

    def flaky_print(*args):
        """Wrapper for print that retries in case of IOError.
        """
        count = 0
        while count < 5:
            count += 1
            try:
                orig_print(*args)
                break
            except IOError:
                if count >= 5:
                    raise
                pass
    orig_print = builtins.print
    builtins.print = flaky_print
    print("Installed wrapper for flaky print.")


# apparently importlib does not exist in python 2.6...
try:
    import importlib
except ImportError:
    # we are on python 2.6
    print("If you want to test the examples, please install importlib from "
          "pypi\n\npip install importlib\n\n")
    pass

files = utils.buildFileList(utils.examples)
frontends = {Qt.PYQT4: False, Qt.PYQT5: False, Qt.PYSIDE: False, Qt.PYSIDE2: False}
# sort out which of the front ends are available
for frontend in frontends.keys():
    try:
        importlib.import_module(frontend)
        frontends[frontend] = True
    except ImportError:
        pass


@pytest.mark.parametrize(
    "frontend, f", itertools.product(sorted(list(frontends.keys())), files))
def test_examples(frontend, f):
    # Test the examples with all available front-ends
    print('frontend = %s. f = %s' % (frontend, f))
    if not frontends[frontend]:
        pytest.skip('%s is not installed. Skipping tests' % frontend)
    utils.testFile(f[0], f[1], utils.sys.executable, frontend)

if __name__ == "__main__":
    pytest.cmdline.main()