Accessing argparse arguments from the class

Question

I have the following sample code running unit tests:

#!/usr/bin/env python3

import sys
import unittest
import argparse

class ParentTest(unittest.TestCase):
    None

class Test1(ParentTest):
    def test_if_verbose(self):
        import __main__ # FIXME
        print("Success!") if __main__.args.verbose else "" # FIXME

class Test2(ParentTest):
    None

if __name__ == '__main__':
    # Parse arguments.
    parser = argparse.ArgumentParser(add_help=False)
    parser.add_argument("-?", "--help",     action="help",                        help="show this help message and exit" )
    parser.add_argument("-v", "--verbose",  action="store_true", dest="verbose",  help="increase output verbosity" )
    parser.add_argument('files', nargs='*')
    args = parser.parse_args()

    print(args.verbose)

    # Add tests.
    alltests = unittest.TestSuite()
    alltests.addTest(unittest.makeSuite(Test1))
    alltests.addTest(unittest.makeSuite(Test2))

    result = unittest.TextTestRunner(verbosity=2).run(alltests) # Run tests.
    sys.exit(not result.wasSuccessful())

and I'd like to access command-line argument values from the class.

In here it's suggested that using __main__ isn't really a good approach.

Is there any better way of doing it, where individual tests could have access to argument values which were parsed already in main?

Testing:

python3 test.py
python3 test.py -v

Community · Accepted Answer · 2017-05-23 12:40:53Z

You could do this by making the test classes take args as parameter, and crafting a custom make_suite method instead of unittest.makeSuite, like this:

class ParentTest(unittest.TestCase):
    def __init__(self, methodName='runTest', args=None):
        super().__init__(methodName)
        self.args = args

class Test1(ParentTest):
    def test_if_verbose(self):
        print("Success!") if self.args.verbose else ""

class Test2(ParentTest):
    pass

if __name__ == '__main__':
    parser = argparse.ArgumentParser(add_help=False)
    parser.add_argument("-?", "--help",     action="help",                        help="show this help message and exit" )
    parser.add_argument("-v", "--verbose",  action="store_true", dest="verbose",  help="increase output verbosity" )
    parser.add_argument('files', nargs='*')
    args = parser.parse_args()

    print(args.verbose)

    def make_suite(testcase_class):
        testloader = unittest.TestLoader()
        testnames = testloader.getTestCaseNames(testcase_class)
        suite = unittest.TestSuite()
        for name in testnames:
            suite.addTest(testcase_class(name, args=args))
        return suite

    # Add tests.
    alltests = unittest.TestSuite()
    alltests.addTest(make_suite(Test1))
    alltests.addTest(make_suite(Test2))

    result = unittest.TextTestRunner(verbosity=2).run(alltests) # Run tests.
    sys.exit(not result.wasSuccessful())

The sample output is the same as the original code:

$ python t2.py ; python t2.py -v
False
test_if_verbose (__main__.Test1) ... ok

----------------------------------------------------------------------
Ran 1 test in 0.000s

OK
True
test_if_verbose (__main__.Test1) ... Success!
ok

----------------------------------------------------------------------
Ran 1 test in 0.000s

OK

The code in my answer was inspired by these posts:

super()__init__ should be super(ParentTest,self)__init__? apart from this, this is a great example — Gang
– Gang, Commented May 8, 2016 at 17:17

vashekcz · Accepted Answer · 2015-05-23 09:16:14Z

Why not just access args directly as a global variable, instead of through __main__? If this is all just a single file -- which means it is one module called __main__ -- then you don't need to import anything. Instead of this:

def test_if_verbose(self):
    import __main__ # FIXME
    print("Success!") if __main__.args.verbose else "" # FIXME

Just do this:

def test_if_verbose(self):
    print("Success!") if args.verbose else ""

Of course, that will only work as long as you don't split the code into modules. janos's solution looks cleaner and doesn't have that restriction -- I just wanted to point out that in this particular case, technically, a simpler way exists.

Stack Exchange Network

Accessing argparse arguments from the class

2 Answers 2

You must log in to answer this question.

Hot Network Questions

Accessing argparse arguments from the class

2 Answers 2

You must log in to answer this question.

Related

Hot Network Questions