Function flatten_grouping

dash/_grouping.py:20–60

Convert a grouping value to a list of scalar values :param grouping: grouping value to flatten :param schema: If provided, a grouping value representing the expected structure of the input grouping value. If not provided, the grouping value is its own schema. A schema i

(grouping, schema=None)

def flatten_grouping(grouping, schema=None):
    """
    Convert a grouping value to a list of scalar values

    :param grouping: grouping value to flatten
    :param schema: If provided, a grouping value representing the expected structure of
        the input grouping value. If not provided, the grouping value is its own schema.
        A schema is required in order to be able treat tuples and dicts in the input
        grouping as scalar values.

    :return: list of the scalar values in the input grouping
    """
    stack = []
    result = []

    # Avoid repeated recursive Python calls by using an explicit stack
    push = stack.append
    pop = stack.pop

    # Only validate once at the top if schema is provided
    if schema is None:
        schema = grouping
    else:
        validate_grouping(grouping, schema)

    push((grouping, schema))
    while stack:
        group, sch = pop()
        # Inline isinstance checks for perf
        typ = type(sch)
        if typ is tuple or typ is list:
            # Avoid double recursion / excessive list construction
            for ge, se in zip(group, sch):
                push((ge, se))
        elif typ is dict:
            for k in sch:
                push((group[k], sch[k]))
        else:
            result.append(group)
    result.reverse()  # Since we LIFO, leaf values are in reverse order
    return result


def grouping_len(grouping):