Python unitest - Use variables defined in module and class level setup functions, in tests

Question

I am doing Python unit testing using nosetests to experiment with Python class and module fixtures, to have minimal setup across my tests.

The problem is I am not sure how to use any variables defined in the setupUpModule and the setUpClass functions in my tests (example: test_1).

This is what I am using to try out:

import unittest  def setUpModule():     a = "Setup Module variable"     print "Setup Module"  def tearDownModule():     print "Closing Module"  class TrialTest(unittest.TestCase):     @classmethod     def setUpClass(cls):         print a #<======         b = "Setup Class variable"      @classmethod     def tearDownClass(cls):         print "Closing Setup Class"      def test_1(self):         print "in test 1"         print a #<======         print b #<======      def test_2(self):         print "in test 2"      def test_3(self):         print "in test 3"      def test_4(self):         print "in test 4"      def test_5(self):         print "in test 5"  if __name__ == "__main__":     unittest.main() 

The error I get is:

Setup Module ERROR Closing Module  ====================================================================== ERROR: test suite for <class 'one_setup.TrialTest'> ---------------------------------------------------------------------- Traceback (most recent call last):   File "/Library/Python/2.7/site-packages/nose/suite.py", line 208, in run     self.setUp()   File "/Library/Python/2.7/site-packages/nose/suite.py", line 291, in setUp     self.setupContext(ancestor)   File "/Library/Python/2.7/site-packages/nose/suite.py", line 314, in setupContext     try_run(context, names)   File "/Library/Python/2.7/site-packages/nose/util.py", line 469, in try_run     return func()   File "/Users/patila14/Desktop/experimental short scripts/one_setup.py", line 13, in setUpClass     print a NameError: global name 'a' is not defined  ---------------------------------------------------------------------- 

Of course, if I do gloabl a and global b, it will work. Is there a better way?

Answer 1

For the string variable a, the only solution is global a. If you look at the Python 2 and Python 3 source code, setupModule() doesn't appear to do anything magical, so all the usual namespace rules apply.

If a were a mutable variable, like a list, you could define it at global scope and then append to it within setupModule.

Variable b is easier to work with because it is defined within a class. Try this:

@classmethod def setUpClass(cls):     cls.b = "Setup Class variable"  def test_1(self):     print self.b