Tidy comparisons, statement layout and a redundant alias (E711, E712, E701, PLC0414)

Hand written rather than autofixed, since three of the four need the
surrounding code read to be sure they are equivalent:

- confetty: `powerstate == None` -> `is None`.
- nodeconfig: `setmode != True` / `!= False` -> `not setmode` / `setmode`.
  Safe because setmode only ever holds None, True or False, and the two
  lines above each test normalise None away first.
- pam: split two `if cond: stmt` one-liners.
- imgutil: `from shutil import copytree as copytree`, an alias that renames
  nothing.  Not a re-export marker, this is a script.

confluent_client/bin/confetty

@@ -1042,7 +1042,7 @@ def main():
                     except IOError:
                         pass
             if powerstate is None or powertime < time.time() - 10:  # Check powerstate every 10 seconds
-                if powerstate == None:
+                if powerstate is None:
                     powerstate = True
                 powertime = time.time()
                 check_power_state()

confluent_client/bin/nodeconfig

@@ -170,7 +170,7 @@ def parse_config_line(arguments, single=False):
         if '=' in param or param[-1] == ':' or forceset:
             if setmode is None:
                 setmode = True
-            if setmode != True:
+            if not setmode:
                 bailout('Cannot do set and query in same command: Query detected but "{0}" appears to be set'.format(param))
             if '=' in param:
                 key, _, value = param.partition('=')
@@ -182,7 +182,7 @@ def parse_config_line(arguments, single=False):
         else:
             if setmode is None:
                 setmode = False
-            if setmode != False:
+            if setmode:
                 bailout('Cannot do set and query in same command: Set mode detected but "{0}" appears to be a query'.format(param))
             if '.' not in param:
                 if param == 'bmc':

confluent_server/confluent/pam.py

@@ -178,8 +178,10 @@ class pam():
             return 0
 
         # python3 ctypes prefers bytes
-        if isinstance(username, str): username = username.encode(encoding)
-        if isinstance(service, str):  service  = service.encode(encoding)
+        if isinstance(username, str):
+            username = username.encode(encoding)
+        if isinstance(service, str):
+            service = service.encode(encoding)
 
         if b'\x00' in username or b'\x00' in service:
             self.code = 4  # PAM_SYSTEM_ERR in Linux-PAM

imgutil/imgutil

@@ -5,7 +5,7 @@ import ctypes
 import ctypes.util
 import datetime
 import inspect
-from shutil import copytree as copytree
+from shutil import copytree
 if hasattr(inspect, 'getfullargspec') and 'dirs_exist_ok' in inspect.getfullargspec(copytree).args:
     def copy_tree(src, dst):
         copytree(src, dst, dirs_exist_ok=True)