# ItemizedResource

Resources that contain items in a grid are subclasses of {class}`pylabrobot.resources.itemized_resource.ItemizedResource`. This class provides convenient methods for accessing the child-resources, such as by integer or SBS "A1" style-notation, as well as for traversing items in an `ItemizedResource`. Examples of subclasses of `ItemizedResource`s are {class}`pylabrobot.resources.plate.Plate` and {class}`pylabrobot.resources.tip_rack.TipRack`.

To instantiate an `ItemizedResource`, it is convenient to use the `pylabrobot.resources.utils.create_equally_spaced_2d` method to quickly initialize a grid of child-resources in a grid. Here's an example of a simple `ItemizedResource`:

```python
from pylabrobot.resources import ItemizedResource
from pylabrobot.resources.utils import create_equally_spaced_2d
from pylabrobot.resources.well import Well, WellBottomType

plate = ItemizedResource(
  name="plate",
  size_x=127,
  size_y=86,
  size_z=10,
  items=create_equally_spaced_2d(
    Well,                            # the class of the items
    num_items_x=12,
    num_items_y=8,
    dx=12,                           # distance between the first well and the border in the x-axis
    dy=12,                           # distance between the first well and the border in the y-axis
    dz=0,                            # distance between the first well and the border in the z-axis
    item_dx=9,                       # distance between the wells in the x-axis
    item_dy=9,                       # distance between the wells in the y-axis

    bottom_type=WellBottomType.FLAT, # a custom keyword argument passed to the Well initializer
  )
)
```