Why not make all executable python scripts executable using:

#!/usr/bin/env python3
# -*- coding: utf-8 -*-

.hgignore

@@ -22,4 +22,6 @@ test/lib
 test/imap_settings.py
 venv
 launch.json
-settings.json
+settings.json
+# Default ignored files
+.idea/workspace.xml

test/basic_doctest.py

@@ -1,3 +1,6 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+
 """
 >>> import pEp
 >>> me = pEp.Identity("alice.smith@peptest.ch", "Alice Smith", "23")

test/codec_doctest.py

@@ -1,3 +1,6 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+
 """
 >>> import pEp
 >>> def messageToSend(msg):

test/doctest_PYADPT-55.py

@@ -1,3 +1,6 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+
 # Regression test against API breakage
 # colors used to be represented as a simple int
 # NEW: colors are represented by colorvalue enum

test/sync_handshake.py

@@ -1,3 +1,5 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
 # vim: set fileencoding=utf-8 :
 
 """start a handshake test for one simulated device

test/sync_test.py

@@ -1,3 +1,5 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
 # vim: set fileencoding=utf-8 :
 
 """test runner for sync tests