How do I insert a command argument into a string?

Question

I'm trying to figure out how to send a command line argument into a string, and I keep getting an error.

Here is my python code with the command argument

import sys
class LoginTest(unittest.TestCase):
    def setUp(self):
        buildURL = sys.argv[1]
        self.driver = webdriver.Chrome()
        self.driver.get("https://" + buildURL + "test.com")

Here is the command line argument I send.

python test.py build190

And lastly the error I keep getting.

AttributeError: 'module' object has no attribute 'build190'

The full error message I receive

Traceback (most recent call last):
  File "Test.py", line 60, in <module>
    unittest.main()
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/unittest/main.py", line 94, in __init__
    self.parseArgs(argv)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/unittest/main.py", line 149, in parseArgs
    self.createTests()
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/unittest/main.py", line 158, in createTests
    self.module)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/unittest/loader.py", line 130, in loadTestsFromNames
    suites = [self.loadTestsFromName(name, module) for name in names]
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/unittest/loader.py", line 100, in loadTestsFromName
    parent, obj = obj, getattr(obj, part)
AttributeError: 'module' object has no attribute 'build190'

Tried using `buildURL=sys.argv.pop()` or `buildURL=sys.argv[1:]`? — Rahul, Feb 10 '18 at 23:01
Please post the value of the buildURL variable after you assign it a value. Also - does this error happen on the assignment line or when you try to use it at self.driver.get(....) line? — Lee James, Feb 10 '18 at 23:04
@LeeJames The error is well explained in the answer provided. It is the nature of how unittest runs. It is ultimately trying to use/discover the passed argument as a module, hence why that exception is raised. — idjaw, Feb 10 '18 at 23:28
@idjaw when i posted my comment, there was no error information in the question ;) — Lee James, Feb 10 '18 at 23:33
@LeeJames I was referring to the answer provided below. I see my comment did not express that properly. — idjaw, Feb 10 '18 at 23:34
@idjaw - and again - when I posted my comment, there was no answer below :D — Lee James, Feb 10 '18 at 23:37
@LeeJames OK. Sorry for sharing information with you then. ;) :) :D =D — idjaw, Feb 10 '18 at 23:41

Ilija · Accepted Answer · 2018-02-10T23:31:44.573

3

You are trying to run unittest and how it loads is interfering with your intention to pass argument to a script.

Before we go further, unit tests should run as standalone and passing parameters to them is not a best practice. Here you can read reasons why not to do it.

Anyway, try this snippet. It should work.

import sys
import unittest

class LoginTest(unittest.TestCase):
    buildURL = ""

    def setUp(self):
        self.driver = webdriver.Chrome()
        self.driver.get("https://" + buildURL + "test.com")

if __name__ == "__main__":
    LoginTest.buildURL = sys.argv[1]
    unittest.main()

If you decide to go this path (passing parameter to a unit test), you should add some checking if there is any argument at all, and if you want to run with buildURL that is not set.

edited Feb 10 '18 at 23:31

answered Feb 10 '18 at 23:19

Ilija

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2

Good break down. Just to add a minor detail about the exact nature of the error: Ultimately, the *exact* thing that is going on with your error, is that throughout the execution of `main()` and initialization of the unit test, it eventually tries to actually discover/load that argument as a module it expects to be there. For the OP, if you're interested, use your debugger to check out what is going on when main is called, or use `pdb` to step through the code through your command line to see when it breaks. It will make sense when you see it for yourself. – idjaw Feb 10 '18 at 23:26
1

And yes, I agree with the advice of "standalone" execution. I'll go a step further, and think about the nature of the real code that is being tested, and consider mocking too for further isolation and "pure" unit testing. – idjaw Feb 10 '18 at 23:27
Thank you, I've taken your advice and will not pass a parameter to the unit test. – Cal Corbin Feb 11 '18 at 00:01

How do I insert a command argument into a string?

1 Answers1