Flask Testing - why does coverage exclude import statements and decorators?

My tests clearly execute each function, and there are no unused imports either. Yet, according to the coverage report, 62% of the code was never executed in the following file:

Can someone please point out what I might be doing wrong?

Here's how I initialise the test suite and the coverage:

    cov = coverage(branch=True, omit=['website/*', 'run_test_suite.py'])
    cov.start()

    try:
        unittest.main(argv=[sys.argv[0]])
    except:
        pass

    cov.stop()
    cov.save()

    print "\n\nCoverage Report:\n"
    cov.report()

    print "HTML version: " + os.path.join(BASEDIR, "tmp/coverage/index.html")
    cov.html_report(directory='tmp/coverage')
    cov.erase()