Class Category

src/pptx/chart/data.py:509–622

A chart category, primarily having a label to be displayed on the category axis, but also able to be configured in a hierarchy for support of multi-level category charts.

class Category(object):
    """
    A chart category, primarily having a label to be displayed on the
    category axis, but also able to be configured in a hierarchy for support
    of multi-level category charts.
    """

    def __init__(self, label, parent):
        super(Category, self).__init__()
        self._label = label
        self._parent = parent
        self._sub_categories = []

    def add_sub_category(self, label):
        """
        Return a newly created |data.Category| object having *label* and
        appended to the end of the sub-category sequence for this category.
        """
        category = Category(label, self)
        self._sub_categories.append(category)
        return category

    @property
    def depth(self):
        """
        The number of hierarchy levels rooted at this category node. Returns
        1 if this category has no sub-categories.
        """
        sub_categories = self._sub_categories
        if not sub_categories:
            return 1
        first_depth = sub_categories[0].depth
        for category in sub_categories[1:]:
            if category.depth != first_depth:
                raise ValueError("category depth not uniform")
        return first_depth + 1

    @property
    def idx(self):
        """
        The offset of this category in the overall sequence of leaf
        categories. A non-leaf category gets the index of its first
        sub-category.
        """
        return self._parent.index(self)

    def index(self, sub_category):
        """
        The offset of *sub_category* in the overall sequence of leaf
        categories.
        """
        index = self._parent.index(self)
        for this_sub_category in self._sub_categories:
            if sub_category is this_sub_category:
                return index
            index += this_sub_category.leaf_count
        raise ValueError("sub_category not in this category")