Ensure the imports from "domdf_python_tools" do not affect its covera…

…ge measurements.

coverage_pyver_pragma/grammar.py

@@ -120,6 +120,7 @@
 
 # stdlib
 import platform
+import sys
 
 # 3rd party
 import packaging.specifiers
@@ -156,6 +157,17 @@
 		"GRAMMAR",
 		]
 
+# This ensures coverage.py records the correct coverage for these modules
+# when they are under test
+
+for module in [
+		"domdf_python_tools",
+		"domdf_python_tools.doctools",
+		"domdf_python_tools.stringlist",
+		]:
+	if module in sys.modules:
+		del sys.modules[module]
+
 
 @prettify_docstrings
 class VersionTag(packaging.specifiers.SpecifierSet):