ForArrayIndices class

This page explains the ForArrayIndices class.

Before reading on, maybe it is helpful to read the following page (the apysc uses this class for the same reason for each data type):

What class is this?

The ForArrayIndices class is the for-loop class.

This interface returns Array’s index (starts with 0) in a loop.

Basic usage

This class requires using the with-statement.

The as-keyword value becomes the Int type index.

import apysc as ap

ap.Stage(
    stage_width=0,
    stage_height=0,
    background_color=ap.Color("#333"),
    stage_elem_id="stage",
)

arr: ap.Array[ap.Number] = ap.Array([ap.Number(50), ap.Number(150), ap.Number(250)])
indices: ap.Array[ap.Int] = ap.Array([])
with ap.ForArrayIndices(arr=arr) as i:
    indices.append(i)

ap.assert_arrays_equal(indices, [0, 1, 2])

ap.save_overall_html(dest_dir_path="for_array_indices_basic_usage_1/")

The following example uses an index and sets a circle center-x coordinate.

import apysc as ap

ap.Stage(
    stage_width=350,
    stage_height=150,
    background_color=ap.Color("#333"),
    stage_elem_id="stage",
)

x_arr: ap.Array[ap.Number] = ap.Array([ap.Number(75), ap.Number(175), ap.Number(275)])
with ap.ForArrayIndices(arr=x_arr) as i:
    x: ap.Number = x_arr[i]
    circle: ap.Circle = ap.Circle(
        x=x,
        y=75,
        radius=25,
        fill_color=ap.Color("#0af"),
    )

ap.save_overall_html(dest_dir_path="for_array_indices_basic_usage_2/")

See also

ForArrayIndices API

Note: the document build script generates and updates this API document section automatically. Maybe this section is duplicated compared with previous sections.

[Interface signature] __init__(self, arr: apysc._type.array.Array, *, locals_: Union[Dict[str, Any], NoneType] = None, globals_: Union[Dict[str, Any], NoneType] = None, variable_name_suffix: str = '') -> None

[Interface summary]

The loop implementation class for the ap.Array indices.

[Parameters]

  • arr: Array

    • An array to iterate.

  • locals_: Optional[Dict[str, Any]], optional

    • Current scope’s local variables. Set locals() value to this argument. If specified, this interface reverts all local scope VariableNameMixIn variables (like Int, Sprite) at the end of a with-statement scope. This setting is useful when you don’t want to update each variable.

  • globals_: Optional[Dict[str, Any]], optional

    • Current scope’s global variables. Set globals() value to this argument. This setting works the same way as the locals_ argument.

  • variable_name_suffix: str, optional

    • A JavaScript variable name suffix string. This setting is sometimes useful for JavaScript debugging.

[Examples]

>>> import apysc as ap
>>> arr: ap.Array[ap.Number] = ap.Array(
...     [ap.Number(50), ap.Number(150), ap.Number(250)]
... )
>>> indices: ap.Array[ap.Int] = ap.Array([])
>>> with ap.ForArrayIndices(arr=arr) as i:
...     indices.append(i)
...
>>> _ = ap.assert_arrays_equal(indices, [0, 1, 2])

[References]