Source code for xsdata.utils.collections

from collections import defaultdict
from typing import Any
from typing import Callable
from typing import Dict
from typing import List
from typing import Optional
from typing import Sequence


def unique_sequence(items: Sequence, key: Optional[str] = None) -> List:
    seen = set()

    def is_new(val: Any) -> bool:
        if key:
            val = getattr(val, key)

        if val in seen:
            return False

        seen.add(val)
        return True

    return [item for item in items if is_new(item)]


def group_by(items: Sequence, key: Callable) -> Dict[Any, List]:
    result = defaultdict(list)
    for item in items:
        result[key(item)].append(item)
    return result