Updating Objects¶

The Updating Records section shows how to use the update() method to update fields. Another way to accomplish update operations is to update the Record object’s attributes, and call the save() method. The main difference with this approach is that changes are not synced to Nautobot until the save() method is called.

Modifying a Record by Attribute Updates¶

The below example will:

make updates to a Device
show that updates haven’t synced to Nautobot before saving.
show that updates are synced after calling the save method.

>>> device = nautobot.dcim.devices.get(name="hq-access-03")

>>> # Show that device is active
>>> device.status
Active

>>> # Update status and name fields
>>> device.comments = "removed from service"
>>> device.status = "decommissioned"

>>> # Show that changes haven't been synced
>>> tmp_device = nautobot.dcim.devices.get(name="hq-access-03")
>>> tmp_device.status
Active

>>> # Save updates and show that changes have been synced
>>> device.save()
>>> updated_device = nautobot.dcim.devices.get(name="hq-access-03")
>>> updated_device.comments
'removed from service'
>>> updated_device.status
Decommissioned

Errors with updates¶

Since the Update operation behaves similarly to the Create operation, performing an update can have the some of the same errors. The two examples below are the same issues outlined in The Data Sent Does Not Adhere to the Database Schema.

The first example uses the update() method and returns an exception immediately. The second example modifies the objects position attribute, and the exception is not raised until the save() method is called.

Invalid Type¶

>>> # Get a device record
>>> hq_access_5 = devices.get(name="hq-access-05")

>>> # Attempt to update position with an invalid type
>>> hq_access_5.update({"postition": "high"})
Traceback (most recent call last):
...
pynautobot.core.query.RequestError:
The request failed with code 400 Bad Request:
{
  'position': ['A valid integer is required.']
}

Invalid Schema¶

>>> # Get a device record
>>> hq_access_5 = devices.get(name="hq-access-05")

>>> # Attempt to provide invalid rack unit for position
>>> hq_access_5.position = 100

>>> # The exception is only raised when save() is called
>>> hq_access_5.save()
Traceback (most recent call last):
...
pynautobot.core.query.RequestError:
The request failed with code 400 Bad Request:
{
  'position': [
    'U100 is already occupied or does not have sufficient space' \
    'to accommodate this device type: c9300-48 (1U)'
  ]
}

Atomic¶

One important feature of the Nautobot API is that updates are Atomic. If any of the fields being updated causes an error, then all updates are aborted. The following example updates the face and position fields. An error is raised for the position field, and fetching the object from Nautobot shows that face has also been left unchanged.

>>> # Get a device record
>>> hq_access_5 = devices.get(name="hq-access-05")

>>> # Set the face attribute
>>> hq_access_5.face = "front"

>>> # Attempt to provide invalid rack unit for position
>>> hq_access_5.position = 100

>>> # An exception is raised
>>> hq_access_5.save()
Traceback (most recent call last):
...
pynautobot.core.query.RequestError:
The request failed with code 400 Bad Request:
{
  'position': [
    'U100 is already occupied or does not have sufficient space' \
    'to accommodate this device type: c9300-48 (1U)'
  ]
}

>>> # Show that the object's face field has not changed
>>> tmp_hq_access_5 = devices.get(name="hq-access-05")
>>> tmp_hq_access_5.face is None
True

>>> # Fix the position field and retrigger update
>>> hq_access_5.position = 42
>>> hq_access_5.save()
True

>>> # Show that updates have taken affect
>>> tmp_hq_access_5 = devices.get(name="hq-access-05")
>>> tmp_hq_access_5.face
Front
>>> tmp_hq_access_5.position
42