add examples

python/examples/pytest/test_fixture.py

@@ -1,7 +1,9 @@
+import tempfile
+
 def setup_module():
-    print("setup_module")
     global db
-    db = 42
+    db = tempfile.TemporaryDirectory()
+    print(f"setup_module: {db}")
 
 def teardown_module():
     print("teardown_module")

python/examples/pytest/test_functions.out

@@ -0,0 +1,13 @@
+$ pytest -qqs test_functions.py
+
+setup_db <TemporaryDirectory '/tmp/tmppjc3h7k2'>
+    test_one <TemporaryDirectory '/tmp/tmppjc3h7k2'>
+    test_one after
+teardown_db <TemporaryDirectory '/tmp/tmppjc3h7k2'>
+setup_db <TemporaryDirectory '/tmp/tmp_0j_gnnb'>
+    test_two <TemporaryDirectory '/tmp/tmp_0j_gnnb'>
+setup_db <TemporaryDirectory '/tmp/tmpl3gvod_3'>
+    test_three <TemporaryDirectory '/tmp/tmpl3gvod_3'>
+    test_three after
+teardown_db <TemporaryDirectory '/tmp/tmpl3gvod_3'>
+

python/examples/pytest/test_functions.py

@@ -0,0 +1,34 @@
+import tempfile
+
+def test_one():
+    db = setup_db()
+    print(f"    test_one {db}")
+    assert True
+    print("    test_one after")
+    teardown_db(db)
+
+def test_two():
+    db = setup_db()
+    print(f"    test_two {db}")
+    assert False
+    print("    test_two after")
+    teardown_db(db)
+
+def test_three():
+    db = setup_db()
+    print(f"    test_three {db}")
+    assert True
+    print("    test_three after")
+    teardown_db(db)
+
+def setup_db():
+    db = tempfile.TemporaryDirectory()
+    ...
+    print(f"setup_db {db}")
+    return db
+
+def teardown_db(db):
+    ...
+    print(f"teardown_db {db}")
+
+

python/pytest-fixtures.md

@@ -1,8 +1,7 @@
 # PyTest Fixtures
 {id: pytest-fixtures}
 
-
-## PyTest What are Fixtures
+## PyTest: What are Fixtures?
 {id: pytest-what-are-fixture}
 
 * In generally we call [test fixture](https://en.wikipedia.org/wiki/Test_fixture) the environment in which a test is expected to run.
@@ -18,6 +17,18 @@ Specific examples:
 * If I'd like to test the login mechanism, I need that before the test starts running we'll have a verified account in the system.
 * If I test the 3rd element in a pipeline I need the results of the 2nd pipeline to get started and after the test runs I need to remove all those files.
 
+## PyTest: test with functions
+{id: pytest-test-with-functions}
+
+* We need to call the `setup_db()` in every test.
+* We need to call the `teardown_db()` in every test - and it still does not work when the test fails.
+* What if there is some work that needs to be done only once and not for every test?
+
+![](examples/pytest/test_functions.py)
+
+![](examples/pytest/test_functions.out)
+
+
 ## PyTest Fixture setup and teardown xUnit style
 {id: pytest-fixture-setup-teardown}
 {i: setup_function}