python/qemu: delint and add pylintrc

Bring our these files up to speed with pylint 2.5.0.
Add a pylintrc file to formalize which pylint subset
we are targeting.

The similarity ignore is there to suppress similarity
reports across imports, which for typing constants,
are going to trigger this report erroneously.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200528222129.23826-4-jsnow@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>

3 files changed, 88 insertions, 18 deletions

diff --git a/python/qemu/machine.py b/python/qemu/machine.py
index 41554de533..8e4ecd1837 100644
--- a/python/qemu/machine.py
+++ b/python/qemu/machine.py
@@ -58,7 +58,7 @@ class MonitorResponseError(qmp.QMPError):
         self.reply = reply
 
 
-class QEMUMachine(object):
+class QEMUMachine:
     """
     A QEMU VM
 
@@ -239,7 +239,7 @@ class QEMUMachine(object):
                          'chardev=mon,mode=control'])
         if self._machine is not None:
             args.extend(['-machine', self._machine])
-        for i in range(self._console_index):
+        for _ in range(self._console_index):
             args.extend(['-serial', 'null'])
         if self._console_set:
             self._console_address = os.path.join(self._sock_dir,
@@ -374,7 +374,7 @@ class QEMUMachine(object):
                 command = ' '.join(self._qemu_full_args)
             else:
                 command = ''
-            LOG.warning(msg, -exitcode, command)
+            LOG.warning(msg, -int(exitcode), command)
 
         self._launched = False
 
diff --git a/python/qemu/pylintrc b/python/qemu/pylintrc
new file mode 100644
index 0000000000..5d6ae7367d
--- /dev/null
+++ b/python/qemu/pylintrc
@@ -0,0 +1,58 @@
+[MASTER]
+
+[MESSAGES CONTROL]
+
+# Disable the message, report, category or checker with the given id(s). You
+# can either give multiple identifiers separated by comma (,) or put this
+# option multiple times (only on the command line, not in the configuration
+# file where it should appear only once). You can also use "--disable=all" to
+# disable everything first and then reenable specific checks. For example, if
+# you want to run only the similarities checker, you can use "--disable=all
+# --enable=similarities". If you want to run only the classes checker, but have
+# no Warning level messages displayed, use "--disable=all --enable=classes
+# --disable=W".
+disable=too-many-arguments,
+        too-many-instance-attributes,
+        too-many-public-methods,
+
+[REPORTS]
+
+[REFACTORING]
+
+[MISCELLANEOUS]
+
+[LOGGING]
+
+[BASIC]
+
+# Good variable names which should always be accepted, separated by a comma.
+good-names=i,
+           j,
+           k,
+           ex,
+           Run,
+           _,
+           fd,
+
+[VARIABLES]
+
+[STRING]
+
+[SPELLING]
+
+[FORMAT]
+
+[SIMILARITIES]
+
+# Ignore imports when computing similarities.
+ignore-imports=yes
+
+[TYPECHECK]
+
+[CLASSES]
+
+[IMPORTS]
+
+[DESIGN]
+
+[EXCEPTIONS]
diff --git a/python/qemu/qtest.py b/python/qemu/qtest.py
index d24ad04256..53d814c064 100644
--- a/python/qemu/qtest.py
+++ b/python/qemu/qtest.py
@@ -1,5 +1,11 @@
-# QEMU qtest library
-#
+"""
+QEMU qtest library
+
+qtest offers the QEMUQtestProtocol and QEMUQTestMachine classes, which
+offer a connection to QEMU's qtest protocol socket, and a qtest-enabled
+subclass of QEMUMachine, respectively.
+"""
+
 # Copyright (C) 2015 Red Hat Inc.
 #
 # Authors:
@@ -17,19 +23,21 @@ import os
 from .machine import QEMUMachine
 
 
-class QEMUQtestProtocol(object):
-    def __init__(self, address, server=False):
-        """
-        Create a QEMUQtestProtocol object.
+class QEMUQtestProtocol:
+    """
+    QEMUQtestProtocol implements a connection to a qtest socket.
 
-        @param address: QEMU address, can be either a unix socket path (string)
-                        or a tuple in the form ( address, port ) for a TCP
-                        connection
-        @param server: server mode, listens on the socket (bool)
-        @raise socket.error on socket connection errors
-        @note No connection is established, this is done by the connect() or
-              accept() methods
-        """
+    :param address: QEMU address, can be either a unix socket path (string)
+                    or a tuple in the form ( address, port ) for a TCP
+                    connection
+    :param server: server mode, listens on the socket (bool)
+    :raise socket.error: on socket connection errors
+
+    .. note::
+       No conection is estabalished by __init__(), this is done
+       by the connect() or accept() methods.
+    """
+    def __init__(self, address, server=False):
         self._address = address
         self._sock = self._get_sock()
         self._sockfile = None
@@ -73,15 +81,19 @@ class QEMUQtestProtocol(object):
         return resp
 
     def close(self):
+        """Close this socket."""
         self._sock.close()
         self._sockfile.close()
 
     def settimeout(self, timeout):
+        """Set a timeout, in seconds."""
         self._sock.settimeout(timeout)
 
 
 class QEMUQtestMachine(QEMUMachine):
-    '''A QEMU VM'''
+    """
+    A QEMU VM, with a qtest socket available.
+    """
 
     def __init__(self, binary, args=None, name=None, test_dir="/var/tmp",
                  socket_scm_helper=None, sock_dir=None):