CODEWITHSUNDEEP
python
Alex
Alex

Reputation: 731

How to initialize global variable at each class invocation?

I have a module A who looks like the following:

import unittest2

def check_function():
    # performs actions and returns True or False
    return smth

CHECK = check_function()

class A(unittest2.TestCase):

    @unittest2.skipIf(CHECK, "skip message 1")
    def test_1(self):
        # test check

    @unittest2.skipIf(CHECK, "skip message 2")
    def test_2(self):
        # test check

Module A is being imported by another module, called B. When is the global variable CHECK initialized? At import? At class instantiation?

I need to have the CHECK variable set each time class A is called. How can I achieve this?

EDIT: I have tried the following (which might be what I am looking for), but CHECK is not set at all inside setUpClass (it stays False, no matter what check_function() returns).

import unittest2

def check_function():
    # performs actions and returns True or False
    return smth

CHECK = False

class A(unittest2.TestCase):

    global CHECK

    @classmethod
    def setUpClass(cls):
        CHECK = check_function()

    @unittest2.skipIf(CHECK, "skip message 1")
    def test_1(self):
        # test check

    @unittest2.skipIf(CHECK, "skip message 2")
    def test_2(self):
        # test check

Any ideas of how to set CHECK once, each time the test is invoked?

EDIT: check_function() is certainly called once, but I don't understand why unittest2.skipIf does not "see" the value set in setUpClass, and sticks to the False value set at declaration?

SOLUTION:

The final skeletopn of the code looks like this:

import unittest2

def check_function():
    # performs checks and returns True or False
    return smth

class A(unittest2.TestCase):

    CHECK = check_function()

    @unittest2.skipIf(CHECK, "skip message 1")
    def test_1(self):
        # do tests
        self.assertTrue(True)

    @unittest2.skipIf(CHECK, "skip message 1")
    def test_2(self):
        # do tests
        self.assertTrue(True)

Upvotes: 2

Views: 2636

Answers (3)

glglgl
glglgl

Reputation: 91027

Your 2nd approach looks like a starting point. But you are running into timing problems.

On one hand, you want that value to be present on applying the decorators (that's VERY early), on the other hand, you setting it when calling setUpClass(). That is probably quite late.

The only option seems to me to do

class A(unittest2.TestCase):
    CHECK = check_function()

    @unittest2.skipIf(CHECK, "skip message 1")
    def test_1(self):
        # test check

    @unittest2.skipIf(CHECK, "skip message 2")
    def test_2(self):
        # test check

where CHECK is initialized earlier than used.

Upvotes: 1

schacki
schacki

Reputation: 9533

What about this:

import unittest2

def check_function():
  # performs actions and returns True or False
  return smth

CHECK = None

class A(unittest2.TestCase):
    def __init__(self,*args,**kwargs):
        CHECK=check_funtion
        super(A,self).__init__(*args,**kwargs)

    @unittest2.skipIf(CHECK, "skip message 1")
    def test_1(self):
        # test check

    @unittest2.skipIf(CHECK, "skip message 2")
    def test_2(self):
        # test check

Upvotes: 0

defuz
defuz

Reputation: 27611

You CHECK variable initialized when you module import first time.

See example. I have module mymodule.py which contains:

print "i am mymodule"

And some anothermodule.py:

print "first"

import mymodule

print "second"

import mymodule

print "third"

When I run another module.py I get:

first
i am mymodule
second
third

Invitialization variables in python is the same command as print and will be performed line-by-line at the time of the interpreter will be the first time in your module.

More clear example.

mymodule.py:

def get_a():
    print 'init a'
    return 42

def get_b():
    print 'init b'
    return 20

a = get_a()
b = get_b()

anothermodule.py

from mymodule import a
print "a =", a
print "b =", b

Result:

init a
init b
a = 42
Traceback (most recent call last):
  File "anothermodule.py", line 3, in <module>
    print b
NameError: name 'b' is not defined

Upvotes: 2

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