How to share global variables between tests?

Question

I have a global variable in conftest.py and use it in tests. For example:

conftest.py

api_version = 'v25' api_url = 'http://www.foobar.com/' + api_version 

test_foo.py

from conftest import api_url import requests  @pytest.fixture def data():     return requests.request("GET", api_url)  test_bar(data):     assert data is not None 

---

Now I want to be able to change api_version from cmd for testing other api version. So I modified conftest.py in the following way:

conftest.py

api_url = None  def pytest_addoption(parser):     parser.addoption("--api_version", action="store", default="v25", help="By default: v25")  @pytest.fixture(autouse=True, scope='session') def cmd_param(pytestconfig):     api_version = pytestconfig.getoption("--mobile_api_ver").lower()     global api_url     if api_version in ['v24', 'v25', 'v26', 'v27']:         api_url = 'http://www.foobar.com/' + api_version     else:         raise ValueError('Unknown api version: ' + api_version) 

But this doesn't work as I expected because all imports execute before fixtures and test_foo import api_url = None before cmd_param fixture redefines this. Then i write get_api_url method and call it from test module:

conftest.py

api_url = None  def pytest_addoption(parser):     parser.addoption("--api_version", action="store", default="v25", help="By default: v25")  @pytest.fixture(autouse=True, scope='session') def cmd_param(pytestconfig):     api_version = pytestconfig.getoption("--mobile_api_ver").lower()     global api_url     if api_version in ['v24', 'v25', 'v26', 'v27']:         api_url = 'http://www.foobar.com/' + api_version     else:         raise ValueError('Unknown api version: ' + api_version)  def get_api_url():     return api_url 

But now I was forced to change test_foo.py too:

test_foo.py

from conftest import get_api_url import requests  @pytest.fixture def data():      return requests.request("GET", get_api_url())  test_bar(data):     assert data is not None 

It works, but solution looks awkward. Is there a more elegant way to use custom cmd options without changing test files?

Answer 1

According to docs, pytest_namespace has been removed in version 4.0:

One can use pytest_configure to share global variables.

Example:

import pytest  def pytest_configure():     pytest.my_symbol = MySymbol() 

Answer 2

Note: pytest_namespace is deprecated now

pytest provides a way to use some global variables within the session. These variables can be used by fixtures as well.

These variables are controlled via pytest hooks.

import pytest  def pytest_namespace():     return {'my_global_variable': 0}  @pytest.fixture def data():     pytest.my_global_variable = 100  def test(data):     print pytest.my_global_variable