Add python.py coverage injector for ansible-test.

This can be used to run Python scripts from the repository with the
correct interpreter and allow collection of code coverage.

Useful for testing contrib inventory scripts.

test/runner/injector/injector.py

@@ -105,6 +105,8 @@ def main():
 
         if os.path.basename(__file__) == 'injector.py':
             args, env = runner()  # code coverage collection is baked into the AnsiballZ wrapper when needed
+        elif os.path.basename(__file__) == 'python.py':
+            args, env = python()  # run arbitrary python commands using the correct python and with optional code coverage
         else:
             args, env = injector()
 
@@ -119,6 +121,20 @@ def main():
         raise
 
 
+def python():
+    """
+    :rtype: list[str], dict[str, str]
+    """
+    if config.coverage_file:
+        args, env = coverage_command()
+    else:
+        args, env = [config.python_interpreter], os.environ.copy()
+
+    args += config.arguments[1:]
+
+    return args, env
+
+
 def injector():
     """
     :rtype: list[str], dict[str, str]

test/runner/injector/python.py

@@ -0,0 +1 @@
+injector.py