Pylint fixing base_could_client,acloud_main,avd and common_operations.

- fix pylint errors
- Add some pylint disable comments to avoid pylint error temporarily

Bug: None
Test: run pylint
Change-Id: Ibf2ca67631d540cb6dc8d2fa463225cb52860a1e
diff --git a/public/actions/common_operations.py b/public/actions/common_operations.py
index 74ee50c..5a6d1d2 100644
--- a/public/actions/common_operations.py
+++ b/public/actions/common_operations.py
@@ -13,7 +13,6 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
-
 """Common operations between managing GCE and Cuttlefish devices.
 
 This module provides the common operations between managing GCE (device_driver)
@@ -22,7 +21,6 @@
 """
 
 import logging
-import os
 
 from acloud.public import avd
 from acloud.public import errors
@@ -33,127 +31,133 @@
 
 
 def CreateSshKeyPairIfNecessary(cfg):
-  """Create ssh key pair if necessary.
+    """Create ssh key pair if necessary.
 
-  Args:
-    cfg: An Acloudconfig instance.
+    Args:
+        cfg: An Acloudconfig instance.
 
-  Raises:
-    error.DriverError: If it falls into an unexpected condition.
-  """
-  if not cfg.ssh_public_key_path:
-    logger.warning("ssh_public_key_path is not specified in acloud config. "
-                   "Project-wide public key will "
-                   "be used when creating AVD instances. "
-                   "Please ensure you have the correct private half of "
-                   "a project-wide public key if you want to ssh into the "
-                   "instances after creation.")
-  elif cfg.ssh_public_key_path and not cfg.ssh_private_key_path:
-    logger.warning("Only ssh_public_key_path is specified in acloud config, "
-                   "but ssh_private_key_path is missing. "
-                   "Please ensure you have the correct private half "
-                   "if you want to ssh into the instances after creation.")
-  elif cfg.ssh_public_key_path and cfg.ssh_private_key_path:
-    utils.CreateSshKeyPairIfNotExist(cfg.ssh_private_key_path,
-                                     cfg.ssh_public_key_path)
-  else:
-    # Should never reach here.
-    raise errors.DriverError("Unexpected error in CreateSshKeyPairIfNecessary")
+    Raises:
+        error.DriverError: If it falls into an unexpected condition.
+    """
+    if not cfg.ssh_public_key_path:
+        logger.warning(
+            "ssh_public_key_path is not specified in acloud config. "
+            "Project-wide public key will "
+            "be used when creating AVD instances. "
+            "Please ensure you have the correct private half of "
+            "a project-wide public key if you want to ssh into the "
+            "instances after creation.")
+    elif cfg.ssh_public_key_path and not cfg.ssh_private_key_path:
+        logger.warning(
+            "Only ssh_public_key_path is specified in acloud config, "
+            "but ssh_private_key_path is missing. "
+            "Please ensure you have the correct private half "
+            "if you want to ssh into the instances after creation.")
+    elif cfg.ssh_public_key_path and cfg.ssh_private_key_path:
+        utils.CreateSshKeyPairIfNotExist(cfg.ssh_private_key_path,
+                                         cfg.ssh_public_key_path)
+    else:
+        # Should never reach here.
+        raise errors.DriverError(
+            "Unexpected error in CreateSshKeyPairIfNecessary")
 
 
 class DevicePool(object):
-  """A class that manages a pool of virtual devices.
+    """A class that manages a pool of virtual devices.
 
-  Attributes:
-    devices: A list of devices in the pool.
-  """
-
-  def __init__(self, device_factory, devices=None):
-    """Constructs a new DevicePool.
-
-    Args:
-      device_factory: A device factory capable of producing a goldfish or
-        cuttlefish device. The device factory must expose an attribute with
-        the credentials that can be used to retrieve information from the
-        constructed device.
-      devices: List of devices managed by this pool.
-    """
-    self._devices = devices or []
-    self._device_factory = device_factory
-    self._compute_client = device_factory.GetComputeClient()
-
-  def CreateDevices(self, num):
-    """Creates |num| devices for given build_target and build_id.
-
-    Args:
-      num: Number of devices to create.
+    Attributes:
+        devices: A list of devices in the pool.
     """
 
-    # Create host instances for cuttlefish/goldfish device.
-    # Currently one instance supports only 1 device.
-    for _ in range(num):
-      instance = self._device_factory.CreateInstance()
-      ip = self._compute_client.GetInstanceIP(instance)
-      self.devices.append(
-          avd.AndroidVirtualDevice(ip=ip, instance_name=instance))
+    def __init__(self, device_factory, devices=None):
+        """Constructs a new DevicePool.
 
-  def WaitForBoot(self):
-    """Waits for all devices to boot up.
+        Args:
+            device_factory: A device factory capable of producing a goldfish or
+                cuttlefish device. The device factory must expose an attribute with
+                the credentials that can be used to retrieve information from the
+                constructed device.
+            devices: List of devices managed by this pool.
+        """
+        self._devices = devices or []
+        self._device_factory = device_factory
+        self._compute_client = device_factory.GetComputeClient()
 
-    Returns:
-      A dictionary that contains all the failures.
-      The key is the name of the instance that fails to boot,
-      and the value is an errors.DeviceBootError object.
-    """
-    failures = {}
-    for device in self._devices:
-      try:
-        self._compute_client.WaitForBoot(device.instance_name)
-      except errors.DeviceBootError as e:
-        failures[device.instance_name] = e
-    return failures
+    def CreateDevices(self, num):
+        """Creates |num| devices for given build_target and build_id.
 
-  @property
-  def devices(self):
-    """Returns a list of devices in the pool.
+        Args:
+            num: Number of devices to create.
+        """
 
-    Returns:
-      A list of devices in the pool.
-    """
-    return self._devices
+        # Create host instances for cuttlefish/goldfish device.
+        # Currently one instance supports only 1 device.
+        for _ in range(num):
+            instance = self._device_factory.CreateInstance()
+            ip = self._compute_client.GetInstanceIP(instance)
+            self.devices.append(
+                avd.AndroidVirtualDevice(ip=ip, instance_name=instance))
+
+    def WaitForBoot(self):
+        """Waits for all devices to boot up.
+
+        Returns:
+            A dictionary that contains all the failures.
+            The key is the name of the instance that fails to boot,
+            and the value is an errors.DeviceBootError object.
+        """
+        failures = {}
+        for device in self._devices:
+            try:
+                self._compute_client.WaitForBoot(device.instance_name)
+            except errors.DeviceBootError as e:
+                failures[device.instance_name] = e
+        return failures
+
+    @property
+    def devices(self):
+        """Returns a list of devices in the pool.
+
+        Returns:
+            A list of devices in the pool.
+        """
+        return self._devices
 
 
 def CreateDevices(command, cfg, device_factory, num):
-  """Create a set of devices using the given factory.
+    """Create a set of devices using the given factory.
 
-  Args:
-    command: The name of the command, used for reporting.
-    cfg: An AcloudConfig instance.
-    device_factory: A factory capable of producing a single device.
-    num: The number of devices to create.
+    Args:
+        command: The name of the command, used for reporting.
+        cfg: An AcloudConfig instance.
+        device_factory: A factory capable of producing a single device.
+        num: The number of devices to create.
 
-  Returns:
-    A Report instance.
-  """
-  reporter = report.Report(command=command)
-  try:
-    CreateSshKeyPairIfNecessary(cfg)
-    device_pool = DevicePool(device_factory)
-    device_pool.CreateDevices(num)
-    failures = device_pool.WaitForBoot()
-    # Write result to report.
-    for device in device_pool.devices:
-      device_dict = {"ip": device.ip, "instance_name": device.instance_name}
-      if device.instance_name in failures:
-        reporter.AddData(key="devices_failing_boot", value=device_dict)
-        reporter.AddError(str(failures[device.instance_name]))
-      else:
-        reporter.AddData(key="devices", value=device_dict)
-    if failures:
-      reporter.SetStatus(report.Status.BOOT_FAIL)
-    else:
-      reporter.SetStatus(report.Status.SUCCESS)
-  except errors.DriverError as e:
-    reporter.AddError(str(e))
-    reporter.SetStatus(report.Status.FAIL)
-  return reporter
+    Returns:
+        A Report instance.
+    """
+    reporter = report.Report(command=command)
+    try:
+        CreateSshKeyPairIfNecessary(cfg)
+        device_pool = DevicePool(device_factory)
+        device_pool.CreateDevices(num)
+        failures = device_pool.WaitForBoot()
+        # Write result to report.
+        for device in device_pool.devices:
+            device_dict = {
+                "ip": device.ip,
+                "instance_name": device.instance_name
+            }
+            if device.instance_name in failures:
+                reporter.AddData(key="devices_failing_boot", value=device_dict)
+                reporter.AddError(str(failures[device.instance_name]))
+            else:
+                reporter.AddData(key="devices", value=device_dict)
+        if failures:
+            reporter.SetStatus(report.Status.BOOT_FAIL)
+        else:
+            reporter.SetStatus(report.Status.SUCCESS)
+    except errors.DriverError as e:
+        reporter.AddError(str(e))
+        reporter.SetStatus(report.Status.FAIL)
+    return reporter