mpm: Fix various Pylint issues

No functional changes. Fixes for things that PyLint complains about, but
are safe to change anyway, as well as a minor improvement to a docstring
that referenced non-existant args.

This touches files that are mpm.conf-related.

5 files changed, 9 insertions, 13 deletions

diff --git a/mpm/python/usrp_hwd.py b/mpm/python/usrp_hwd.py
index d971cc5fc..f79932231 100755
--- a/mpm/python/usrp_hwd.py
+++ b/mpm/python/usrp_hwd.py
@@ -174,7 +174,7 @@ def main():
         log_default_delta=args.verbose-args.quiet
     ).getChild('main')
     version_string = mpm.__version__
-    if len(mpm.__githash__):
+    if mpm.__githash__:
         version_string += "-g" + mpm.__githash__
     log.info("Launching USRP/MPM, version: %s", version_string)
     if args.init_only:
@@ -189,4 +189,4 @@ def main():
     return spawn_processes(log, args)
 
 if __name__ == '__main__':
-    exit(not main())
+    sys.exit(not main())
diff --git a/mpm/python/usrp_mpm/periph_manager/e320_periphs.py b/mpm/python/usrp_mpm/periph_manager/e320_periphs.py
index 626ee602a..0bda54775 100644
--- a/mpm/python/usrp_mpm/periph_manager/e320_periphs.py
+++ b/mpm/python/usrp_mpm/periph_manager/e320_periphs.py
@@ -353,4 +353,3 @@ class MboardRegsControl(MboardRegsCommon):
         else:
             self.log.trace("RX RF PLL locked")
         return locked
-
diff --git a/mpm/python/usrp_mpm/periph_manager/n3xx.py b/mpm/python/usrp_mpm/periph_manager/n3xx.py
index b87edfac0..ea6274af8 100644
--- a/mpm/python/usrp_mpm/periph_manager/n3xx.py
+++ b/mpm/python/usrp_mpm/periph_manager/n3xx.py
@@ -192,9 +192,6 @@ class n3xx(ZynqComponents, PeriphManagerBase):
         Lists device tree overlays that need to be applied before this class can
         be used. List of strings.
         Are applied in order.
-
-        eeprom_md -- Dictionary of info read out from the mboard EEPROM
-        device_args -- Arbitrary dictionary of info, typically user-defined
         """
         # In the N3xx case, we name the dtbo file the same as the product.
         # N310 -> n310.dtbo, N300 -> n300.dtbo and so on.
@@ -584,8 +581,8 @@ class n3xx(ZynqComponents, PeriphManagerBase):
     def set_time_source(self, time_source):
         " Set a time source "
         clock_source = self._clock_source
-        assert clock_source != None
-        assert time_source != None
+        assert clock_source is not None
+        assert time_source is not None
         if (clock_source, time_source) not in self.valid_sync_sources:
             if time_source == 'sfp0':
                 clock_source = 'internal'
diff --git a/mpm/python/usrp_mpm/prefs.py b/mpm/python/usrp_mpm/prefs.py
index 0e9d636b2..55b6d803d 100644
--- a/mpm/python/usrp_mpm/prefs.py
+++ b/mpm/python/usrp_mpm/prefs.py
@@ -8,7 +8,6 @@ MPM preferences management
 """
 
 import configparser
-from builtins import object
 from usrp_mpm.mpmlog import TRACE, DEBUG, INFO, WARNING, ERROR, CRITICAL
 
 # Store the global preferences object
@@ -19,6 +18,9 @@ MPM_DEFAULT_CONFFILE_PATH = '/etc/uhd/mpm.conf'
 MPM_DEFAULT_LOG_LEVEL = 'info'
 MPM_DEFAULT_LOG_BUF_SIZE = 100 # Number of log records to buf
 
+# ConfigParser has too many parents for PyLint's liking, but we don't control
+# that, so disable that warning
+# pylint: disable=too-many-ancestors
 class _MPMPrefs(configparser.ConfigParser):
     """
     Container for MPM preferences.
@@ -83,6 +85,7 @@ class _MPMPrefs(configparser.ConfigParser):
         because the logger isn't ready yet.
         """
         return self._errors
+# pylint: enable=too-many-ancestors
 
 def get_prefs():
     """
@@ -92,4 +95,3 @@ def get_prefs():
     if _PREFS is None:
         _PREFS = _MPMPrefs()
     return _PREFS
-
diff --git a/mpm/python/usrp_mpm/xports/xportmgr_udp.py b/mpm/python/usrp_mpm/xports/xportmgr_udp.py
index d6f8a47a7..f77e2ce41 100644
--- a/mpm/python/usrp_mpm/xports/xportmgr_udp.py
+++ b/mpm/python/usrp_mpm/xports/xportmgr_udp.py
@@ -8,14 +8,13 @@
 UDP Transport manager
 """
 
-from builtins import object
 from six import iteritems, itervalues
 from usrp_mpm.ethdispatch import EthDispatcherCtrl
 from usrp_mpm.sys_utils import net
 
 DEFAULT_BRIDGE_MODE = False
 
-class XportMgrUDP(object):
+class XportMgrUDP:
     """
     Transport manager for UDP connections
     """
@@ -153,7 +152,6 @@ class XportMgrUDP(object):
 
     def deinit(self):
         " Clean up after a session terminates "
-        pass
 
     def get_xport_info(self):
         """