import collections.abc
import contextlib
+import http.cookies
import inspect
import itertools
import re
+import xml.etree.ElementTree
from ._utils import (
IDENTITY,
>>> obj = [{}, {"key": "value"}]
>>> traverse_obj(obj, (1, "key"))
- "value"
+ 'value'
Each of the provided `paths` is tested and the first producing a valid result will be returned.
The next path will also be tested if the path branched but no results could be found.
- Supported values for traversal are `Mapping`, `Iterable` and `re.Match`.
+ Supported values for traversal are `Mapping`, `Iterable`, `re.Match`,
+ `xml.etree.ElementTree` (xpath) and `http.cookies.Morsel`.
Unhelpful values (`{}`, `None`) are treated as the absence of a value and discarded.
The paths will be wrapped in `variadic`, so that `'key'` is conveniently the same as `('key', )`.
The keys in the path can be one of:
- `None`: Return the current object.
- `set`: Requires the only item in the set to be a type or function,
- like `{type}`/`{func}`. If a `type`, returns only values
- of this type. If a function, returns `func(obj)`.
+ like `{type}`/`{type, type, ...}/`{func}`. If a `type`, return only
+ values of this type. If a function, returns `func(obj)`.
- `str`/`int`: Return `obj[key]`. For `re.Match`, return `obj.group(key)`.
- `slice`: Branch out and return all values in `obj[key]`.
- `Ellipsis`: Branch out and return a list of all values.
For `Iterable`s, `key` is the index of the value.
For `re.Match`es, `key` is the group number (0 = full match)
as well as additionally any group names, if given.
- - `dict` Transform the current object and return a matching dict.
+ - `dict`: Transform the current object and return a matching dict.
Read as: `{key: traverse_obj(obj, path) for key, path in dct.items()}`.
+ - `any`-builtin: Take the first matching object and return it, resetting branching.
+ - `all`-builtin: Take all matching objects and return them as a list, resetting branching.
`tuple`, `list`, and `dict` all support nested paths and branches.
result = obj
elif isinstance(key, set):
- assert len(key) == 1, 'Set should only be used to wrap a single item'
item = next(iter(key))
- if isinstance(item, type):
- if isinstance(obj, item):
+ if len(key) > 1 or isinstance(item, type):
+ assert all(isinstance(item, type) for item in key)
+ if isinstance(obj, tuple(key)):
result = obj
else:
result = try_call(item, args=(obj,))
elif key is ...:
branching = True
+ if isinstance(obj, http.cookies.Morsel):
+ obj = dict(obj, key=obj.key, value=obj.value)
if isinstance(obj, collections.abc.Mapping):
result = obj.values()
- elif is_iterable_like(obj):
+ elif is_iterable_like(obj) or isinstance(obj, xml.etree.ElementTree.Element):
result = obj
elif isinstance(obj, re.Match):
result = obj.groups()
elif callable(key):
branching = True
+ if isinstance(obj, http.cookies.Morsel):
+ obj = dict(obj, key=obj.key, value=obj.value)
if isinstance(obj, collections.abc.Mapping):
iter_obj = obj.items()
- elif is_iterable_like(obj):
+ elif is_iterable_like(obj) or isinstance(obj, xml.etree.ElementTree.Element):
iter_obj = enumerate(obj)
elif isinstance(obj, re.Match):
iter_obj = itertools.chain(
} or None
elif isinstance(obj, collections.abc.Mapping):
+ if isinstance(obj, http.cookies.Morsel):
+ obj = dict(obj, key=obj.key, value=obj.value)
result = (try_call(obj.get, args=(key,)) if casesense or try_call(obj.__contains__, args=(key,)) else
next((v for k, v in obj.items() if casefold(k) == key), None))
result = next((v for k, v in obj.groupdict().items() if casefold(k) == key), None)
elif isinstance(key, (int, slice)):
- if is_iterable_like(obj, collections.abc.Sequence):
+ if is_iterable_like(obj, (collections.abc.Sequence, xml.etree.ElementTree.Element)):
branching = isinstance(key, slice)
with contextlib.suppress(IndexError):
result = obj[key]
with contextlib.suppress(IndexError):
result = str(obj)[key]
+ elif isinstance(obj, xml.etree.ElementTree.Element) and isinstance(key, str):
+ xpath, _, special = key.rpartition('/')
+ if not special.startswith('@') and not special.endswith('()'):
+ xpath = key
+ special = None
+
+ # Allow abbreviations of relative paths, absolute paths error
+ if xpath.startswith('/'):
+ xpath = f'.{xpath}'
+ elif xpath and not xpath.startswith('./'):
+ xpath = f'./{xpath}'
+
+ def apply_specials(element):
+ if special is None:
+ return element
+ if special == '@':
+ return element.attrib
+ if special.startswith('@'):
+ return try_call(element.attrib.get, args=(special[1:],))
+ if special == 'text()':
+ return element.text
+ raise SyntaxError(f'apply_specials is missing case for {special!r}')
+
+ if xpath:
+ result = list(map(apply_specials, obj.iterfind(xpath)))
+ else:
+ result = apply_specials(obj)
+
return branching, result if branching else (result,)
def lazy_last(iterable):
if not casesense and isinstance(key, str):
key = key.casefold()
+ if key in (any, all):
+ has_branched = False
+ filtered_objs = (obj for obj in objs if obj not in (None, {}))
+ if key is any:
+ objs = (next(filtered_objs, None),)
+ else:
+ objs = (list(filtered_objs),)
+ continue
+
if __debug__ and callable(key):
# Verify function signature
inspect.signature(key).bind(None, None)