update to run unit tests from project directory

.vscode/settings.json

@@ -3,7 +3,7 @@
     "python.testing.unittestArgs": [
         "-v",
         "-s",
-        "./C_expressions",
+        ".",
         "-p",
         "test_*.py"
     ],

C_expressions/.vscode/settings.json

+{
+    "python.testing.unittestArgs": [
+        "-v",
+        "-s",
+        ".",
+        "-p",
+        "test_*.py"
+    ],
+    "python.testing.pytestEnabled": false,
+    "python.testing.unittestEnabled": true
+}
\ No newline at end of file

C_expressions/__init__.py

-import os
 """
-Special file __init__.py marks a directory as a Python package.
-A Python Package is a collection of Python modules with an
-__init__.py File. The file is executed once when any .py file
-from the directory is imported for the first time.
+Special file __init__.py marks a directory as a Python module.
+The file is executed once when any .py file is imported.
+//
+Python unittest require the presence of (even an empty) file.
 """
 
-
-def package_dir(file):
-    """
-    Return name of directory of this package.
-    """
-    path = os.path.normpath(file).split(os.sep)
-    return path[len(path)-2]    # e.g. "C_expressions"
-
-
-def project_path(file):
-    """
-    Return path to project directory.
-    """
-    path = os.path.normpath(file).split(os.sep)
-    return os.path.dirname(file)[:-len(PACKAGE_DIR)-1]
-
-
-def import_sol_module(file):
-    """
-    Import and return module with name "file + '_sol'".
-    Raises ImportError exception, if _sol file does not exist.
-    """
-    sol_module = (file.split("\\")[-1:])[0].split(".")[0] + "_sol"
-    return __import__(sol_module, globals(), locals(), [], 0)
-
-
-# name of this package directory
-PACKAGE_DIR = package_dir(__file__)
-
-# path to project directory, in which this module resides 
-PROJECT_PATH = project_path(__file__)
+# load setup module when executed in parent directory
+try:
+    __import__('setup')
+#
+except ImportError:
+    pass

C_expressions/expressions.py

@@ -61,9 +61,9 @@ class Expressions:
 
         # attempt to load solution module (ignore)
         try:
-            sol_module = (__file__.split("\\")[-1:])[0].split(".")[0] + "_sol"
-            mod = __import__(sol_module, globals(), locals(), [], 0)
-            mod.set_solution(self)  # replace empty values with solutions
+            _from, _import = 'expressions_sol', 'Stream'
+            mod = __import__(_from, fromlist=[_import])
+            mod.set_solution(self)  # invoke set_solution() to replace values with solutions
         #
         except ImportError:
             pass