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Diffstat (limited to 'third_party/python/attrs/attr/_funcs.py')
| -rw-r--r-- | third_party/python/attrs/attr/_funcs.py | 290 |
1 files changed, 290 insertions, 0 deletions
diff --git a/third_party/python/attrs/attr/_funcs.py b/third_party/python/attrs/attr/_funcs.py new file mode 100644 index 0000000000..c077e4284f --- /dev/null +++ b/third_party/python/attrs/attr/_funcs.py @@ -0,0 +1,290 @@ +from __future__ import absolute_import, division, print_function + +import copy + +from ._compat import iteritems +from ._make import NOTHING, _obj_setattr, fields +from .exceptions import AttrsAttributeNotFoundError + + +def asdict( + inst, + recurse=True, + filter=None, + dict_factory=dict, + retain_collection_types=False, +): + """ + Return the ``attrs`` attribute values of *inst* as a dict. + + Optionally recurse into other ``attrs``-decorated classes. + + :param inst: Instance of an ``attrs``-decorated class. + :param bool recurse: Recurse into classes that are also + ``attrs``-decorated. + :param callable filter: A callable whose return code determines whether an + attribute or element is included (``True``) or dropped (``False``). Is + called with the `attr.Attribute` as the first argument and the + value as the second argument. + :param callable dict_factory: A callable to produce dictionaries from. For + example, to produce ordered dictionaries instead of normal Python + dictionaries, pass in ``collections.OrderedDict``. + :param bool retain_collection_types: Do not convert to ``list`` when + encountering an attribute whose type is ``tuple`` or ``set``. Only + meaningful if ``recurse`` is ``True``. + + :rtype: return type of *dict_factory* + + :raise attr.exceptions.NotAnAttrsClassError: If *cls* is not an ``attrs`` + class. + + .. versionadded:: 16.0.0 *dict_factory* + .. versionadded:: 16.1.0 *retain_collection_types* + """ + attrs = fields(inst.__class__) + rv = dict_factory() + for a in attrs: + v = getattr(inst, a.name) + if filter is not None and not filter(a, v): + continue + if recurse is True: + if has(v.__class__): + rv[a.name] = asdict( + v, True, filter, dict_factory, retain_collection_types + ) + elif isinstance(v, (tuple, list, set)): + cf = v.__class__ if retain_collection_types is True else list + rv[a.name] = cf( + [ + _asdict_anything( + i, filter, dict_factory, retain_collection_types + ) + for i in v + ] + ) + elif isinstance(v, dict): + df = dict_factory + rv[a.name] = df( + ( + _asdict_anything( + kk, filter, df, retain_collection_types + ), + _asdict_anything( + vv, filter, df, retain_collection_types + ), + ) + for kk, vv in iteritems(v) + ) + else: + rv[a.name] = v + else: + rv[a.name] = v + return rv + + +def _asdict_anything(val, filter, dict_factory, retain_collection_types): + """ + ``asdict`` only works on attrs instances, this works on anything. + """ + if getattr(val.__class__, "__attrs_attrs__", None) is not None: + # Attrs class. + rv = asdict(val, True, filter, dict_factory, retain_collection_types) + elif isinstance(val, (tuple, list, set)): + cf = val.__class__ if retain_collection_types is True else list + rv = cf( + [ + _asdict_anything( + i, filter, dict_factory, retain_collection_types + ) + for i in val + ] + ) + elif isinstance(val, dict): + df = dict_factory + rv = df( + ( + _asdict_anything(kk, filter, df, retain_collection_types), + _asdict_anything(vv, filter, df, retain_collection_types), + ) + for kk, vv in iteritems(val) + ) + else: + rv = val + return rv + + +def astuple( + inst, + recurse=True, + filter=None, + tuple_factory=tuple, + retain_collection_types=False, +): + """ + Return the ``attrs`` attribute values of *inst* as a tuple. + + Optionally recurse into other ``attrs``-decorated classes. + + :param inst: Instance of an ``attrs``-decorated class. + :param bool recurse: Recurse into classes that are also + ``attrs``-decorated. + :param callable filter: A callable whose return code determines whether an + attribute or element is included (``True``) or dropped (``False``). Is + called with the `attr.Attribute` as the first argument and the + value as the second argument. + :param callable tuple_factory: A callable to produce tuples from. For + example, to produce lists instead of tuples. + :param bool retain_collection_types: Do not convert to ``list`` + or ``dict`` when encountering an attribute which type is + ``tuple``, ``dict`` or ``set``. Only meaningful if ``recurse`` is + ``True``. + + :rtype: return type of *tuple_factory* + + :raise attr.exceptions.NotAnAttrsClassError: If *cls* is not an ``attrs`` + class. + + .. versionadded:: 16.2.0 + """ + attrs = fields(inst.__class__) + rv = [] + retain = retain_collection_types # Very long. :/ + for a in attrs: + v = getattr(inst, a.name) + if filter is not None and not filter(a, v): + continue + if recurse is True: + if has(v.__class__): + rv.append( + astuple( + v, + recurse=True, + filter=filter, + tuple_factory=tuple_factory, + retain_collection_types=retain, + ) + ) + elif isinstance(v, (tuple, list, set)): + cf = v.__class__ if retain is True else list + rv.append( + cf( + [ + astuple( + j, + recurse=True, + filter=filter, + tuple_factory=tuple_factory, + retain_collection_types=retain, + ) + if has(j.__class__) + else j + for j in v + ] + ) + ) + elif isinstance(v, dict): + df = v.__class__ if retain is True else dict + rv.append( + df( + ( + astuple( + kk, + tuple_factory=tuple_factory, + retain_collection_types=retain, + ) + if has(kk.__class__) + else kk, + astuple( + vv, + tuple_factory=tuple_factory, + retain_collection_types=retain, + ) + if has(vv.__class__) + else vv, + ) + for kk, vv in iteritems(v) + ) + ) + else: + rv.append(v) + else: + rv.append(v) + return rv if tuple_factory is list else tuple_factory(rv) + + +def has(cls): + """ + Check whether *cls* is a class with ``attrs`` attributes. + + :param type cls: Class to introspect. + :raise TypeError: If *cls* is not a class. + + :rtype: bool + """ + return getattr(cls, "__attrs_attrs__", None) is not None + + +def assoc(inst, **changes): + """ + Copy *inst* and apply *changes*. + + :param inst: Instance of a class with ``attrs`` attributes. + :param changes: Keyword changes in the new copy. + + :return: A copy of inst with *changes* incorporated. + + :raise attr.exceptions.AttrsAttributeNotFoundError: If *attr_name* couldn't + be found on *cls*. + :raise attr.exceptions.NotAnAttrsClassError: If *cls* is not an ``attrs`` + class. + + .. deprecated:: 17.1.0 + Use `evolve` instead. + """ + import warnings + + warnings.warn( + "assoc is deprecated and will be removed after 2018/01.", + DeprecationWarning, + stacklevel=2, + ) + new = copy.copy(inst) + attrs = fields(inst.__class__) + for k, v in iteritems(changes): + a = getattr(attrs, k, NOTHING) + if a is NOTHING: + raise AttrsAttributeNotFoundError( + "{k} is not an attrs attribute on {cl}.".format( + k=k, cl=new.__class__ + ) + ) + _obj_setattr(new, k, v) + return new + + +def evolve(inst, **changes): + """ + Create a new instance, based on *inst* with *changes* applied. + + :param inst: Instance of a class with ``attrs`` attributes. + :param changes: Keyword changes in the new copy. + + :return: A copy of inst with *changes* incorporated. + + :raise TypeError: If *attr_name* couldn't be found in the class + ``__init__``. + :raise attr.exceptions.NotAnAttrsClassError: If *cls* is not an ``attrs`` + class. + + .. versionadded:: 17.1.0 + """ + cls = inst.__class__ + attrs = fields(cls) + for a in attrs: + if not a.init: + continue + attr_name = a.name # To deal with private attributes. + init_name = attr_name if attr_name[0] != "_" else attr_name[1:] + if init_name not in changes: + changes[init_name] = getattr(inst, attr_name) + return cls(**changes) |