python: PEP 8: adapt empty lines

Add or remove empty lines to match the needed ones around
blocks/functions/etc.

Adapt the generation of guestfs.py to emit the separating empty line
before adding a new function/alias, rather than after it.

This is just formatting, no behaviour changes.

python/t/test020Create.py

@@ -18,6 +18,7 @@
 import unittest
 import guestfs
 
+
 class Test020Create(unittest.TestCase):
     def test_create(self):
         _ = guestfs.GuestFS(python_return_dict=True)

python/t/test030CreateFlags.py

@@ -18,6 +18,7 @@
 import unittest
 import guestfs
 
+
 class Test030CreateFlags(unittest.TestCase):
     def test_create_flags(self):
         g = guestfs.GuestFS(python_return_dict=True,

python/t/test040CreateMultiple.py

@@ -18,9 +18,11 @@
 import unittest
 import guestfs
 
+
 def ignore(_):
     pass
 
+
 class Test040CreateMultiple(unittest.TestCase):
     def test_create_multiple(self):
         g1 = guestfs.GuestFS(python_return_dict=True)

python/t/test050HandleProperties.py

@@ -19,6 +19,7 @@ import unittest
 import warnings
 import guestfs
 
+
 class Test050HandleProperties(unittest.TestCase):
     def test_verbose(self):
         g = guestfs.GuestFS(python_return_dict=True)

python/t/test430ProgressMessages.py

@@ -21,10 +21,12 @@ import guestfs
 
 callback_invoked = 0
 
+
 def callback(ev, eh, buf, array):
     global callback_invoked
     callback_invoked += 1
 
+
 class Test430ProgressMessages(unittest.TestCase):
     def test_progress_messages(self):
         global callback_invoked