For this recipe, we need to declare a list of tests, as follows:

1. CMakeLists.txt is very brief:

# set minimum cmake version
cmake_minimum_required(VERSION 3.5 FATAL_ERROR)

# project name
project(recipe-08 LANGUAGES NONE)

# detect python
find_package(PythonInterp REQUIRED)

# define tests
enable_testing()

add_test(a ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/test/a.py)
add_test(b ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/test/b.py)
add_test(c ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/test/c.py)
add_test(d ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/test/d.py)
add_test(e ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/test/e.py)
add_test(f ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/test/f.py)
add_test(g ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/test/g.py)
add_test(h ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/test/h.py)
add_test(i ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/test/i.py)
add_test(j ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/test/j.py)

2. We can configure the project and run the tests using ctest, which takes 17 seconds in total:

$ mkdir -p build
$ cd build
$ cmake ..
$ ctest

      Start 1: a
 1/10 Test #1: a ................................ Passed 0.51 sec
      Start 2: b
 2/10 Test #2: b ................................ Passed 0.51 sec
      Start 3: c
 3/10 Test #3: c ................................ Passed 0.51 sec
      Start 4: d
 4/10 Test #4: d ................................ Passed 0.51 sec
      Start 5: e
 5/10 Test #5: e ................................ Passed 1.51 sec
      Start 6: f
 6/10 Test #6: f ................................ Passed 1.51 sec
      Start 7: g
 7/10 Test #7: g ................................ Passed 1.51 sec
      Start 8: h
 8/10 Test #8: h ................................ Passed 2.51 sec
      Start 9: i
 9/10 Test #9: i ................................ Passed 3.51 sec
      Start 10: j
10/10 Test #10: j ................................ Passed 4.51 sec

100% tests passed, 0 tests failed out of 10
  
Total Test time (real) = 17.11 sec

3. Now, if we happen to have four cores available, we can run the test set on four cores in less than five seconds:

$ ctest --parallel 4

      Start 10: j
      Start 9: i
      Start 8: h
      Start 5: e
 1/10 Test #5: e ................................ Passed 1.51 sec
      Start 7: g
 2/10 Test #8: h ................................ Passed 2.51 sec
      Start 6: f
 3/10 Test #7: g ................................ Passed 1.51 sec
      Start 3: c
 4/10 Test #9: i ................................ Passed 3.63 sec
 5/10 Test #3: c ................................ Passed 0.60 sec
      Start 2: b
      Start 4: d
 6/10 Test #6: f ................................ Passed 1.51 sec
 7/10 Test #4: d ................................ Passed 0.59 sec
 8/10 Test #2: b ................................ Passed 0.59 sec
      Start 1: a
 9/10 Test #10: j ................................ Passed 4.51 sec
10/10 Test #1: a ................................ Passed 0.51 sec

100% tests passed, 0 tests failed out of 10

Total Test time (real) = 4.74 sec