group

class janim.items.group.Group(*items: T, **kwargs)

Bases: Points, Generic[T]

Item group

Group items together

static from_iterable(items: Iterable, **kwargs) → Group
class janim.items.group.NamedGroupMixin(*items: T, named: dict[str, T], **kwargs)

Bases: Group, Generic

A convenient base class for inheritance, for example by Axes

See also: NamedGroup

add(*items: T, prepend=False, **named_items: T) → Self

Add child items to this item, and set named child items via keyword arguments

Parameters:

  • items – Child items to add

  • named_items – Named child items to add

  • prepend – Default is False; if True, insert at the beginning of the child-item list

insert(index: int, *items: T, **named_items: T) → Self

Insert child items at the specified index, and set named child items via keyword arguments

Parameters:

  • index – Index at which to insert

  • items – Child items to insert

  • named_items – Named child items to insert

remove(*items_or_names: T | str) → Self

Remove child items from this item

Parameters:

items_or_names – Child items or names of named child items to remove

shuffle() → Self

Randomly shuffle the order of child items

Note

This method uses random.shuffle() to shuffle

For reproducible randomness, set the seed with random.seed() before calling this method

set_name(item: Item, name: str) → Self

Set the name for an existing child item

Parameters:

  • item – An existing child item

  • name – The name to set

by_name(key: str) → T

Get a child item by name

resolve() → dict[str, T]

Resolve the internal index mapping of named child items into a name-to-item map

Returns:

A mapping dictionary from names to child items

children_with_name() → list[tuple[T, str | None]]

Returns a list similar to the children list, but each element is a tuple of (child item, its name). If the child item is not named, the name is None

store(**kwargs)
restore(other: NamedGroupMixin) → Self
get_named_indices() → dict[str, int]
copy(*, root_only: bool = False)

Copy the item

class janim.items.group.NamedGroup(*items: T, **named_items: T)

Bases: NamedGroupMixin, Generic

Named item group; you can access named items with syntax like group['name']

Parameters:

  • items – Initial items

  • named_items – Initial named items

You can also use add() or insert() and pass keyword arguments to add named child items

Example:

group = NamedGroup(
    text=Text('lorem'),
    shape=Circle()
)
group.points.arrange(DOWN, aligned_edge=LEFT)

self.play(
    group['text'].anim.color.set(GREEN),
    group['shape'].anim.color.set(YELLOW),
    lag_ratio=0.5
)

def updater(group: NamedGroup, p: UpdaterParams) -> None:
    group.points.rotate(TAU * p.alpha)
    group['text'].color.mix(BLUE, p.alpha)

self.play(
    GroupUpdater(group, updater)
)

Note

Cannot use initialization parameters like Group

group = Group(..., color=RED)

To resolve this, you can write:

group = NamedGroup(...)
group.set(color=RED)

Note

If you want to subclass NamedGroup, using NamedGroupMixin is a better choice

Because it does not consume all **kwargs; instead it uses an explicit named parameter to specify the named child-item dictionary