Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.11/site-packages/astroid/interpreter/dunder_lookup.py: 71%

1# Licensed under the LGPL: https://www.gnu.org/licenses/old-licenses/lgpl-2.1.en.html 

2# For details: https://github.com/pylint-dev/astroid/blob/main/LICENSE 

3# Copyright (c) https://github.com/pylint-dev/astroid/blob/main/CONTRIBUTORS.txt 

4 

5"""Contains logic for retrieving special methods. 

6 

7This implementation does not rely on the dot attribute access 

8logic, found in ``.getattr()``. The difference between these two 

9is that the dunder methods are looked with the type slots 

10(you can find more about these here 

11http://lucumr.pocoo.org/2014/8/16/the-python-i-would-like-to-see/) 

12As such, the lookup for the special methods is actually simpler than 

13the dot attribute access. 

14""" 

15 

16from __future__ import annotations 

17 

18import itertools 

19from typing import TYPE_CHECKING 

20 

21import astroid 

22from astroid import nodes 

23from astroid.exceptions import AttributeInferenceError 

24 

25if TYPE_CHECKING: 

26 from astroid.context import InferenceContext 

27 

28 

29def _lookup_in_mro(node, name) -> list: 

30 attrs = node.locals.get(name, []) 

31 

32 nodes_ = itertools.chain.from_iterable( 

33 ancestor.locals.get(name, []) for ancestor in node.ancestors(recurs=True) 

34 ) 

35 values = list(itertools.chain(attrs, nodes_)) 

36 if not values: 

37 raise AttributeInferenceError(attribute=name, target=node) 

38 

39 return values 

40 

41 

42def lookup( 

43 node: nodes.NodeNG, name: str, context: InferenceContext | None = None 

44) -> list: 

45 """Lookup the given special method name in the given *node*. 

46 

47 If the special method was found, then a list of attributes 

48 will be returned. Otherwise, `astroid.AttributeInferenceError` 

49 is going to be raised. 

50 """ 

51 if isinstance(node, (nodes.List, nodes.Tuple, nodes.Const, nodes.Dict, nodes.Set)): 

52 return _builtin_lookup(node, name) 

53 if isinstance(node, astroid.Instance): 

54 return _lookup_in_mro(node, name) 

55 if isinstance(node, nodes.ClassDef): 

56 return _class_lookup(node, name, context=context) 

57 

58 raise AttributeInferenceError(attribute=name, target=node) 

59 

60 

61def _class_lookup( 

62 node: nodes.ClassDef, name: str, context: InferenceContext | None = None 

63) -> list: 

64 metaclass = node.metaclass(context=context) 

65 # An explicit metaclass may infer to a non-class node (e.g. a function), 

66 # which has no MRO to look the special method up in. 

67 if not isinstance(metaclass, nodes.ClassDef): 

68 raise AttributeInferenceError(attribute=name, target=node) 

69 

70 return _lookup_in_mro(metaclass, name) 

71 

72 

73def _builtin_lookup(node, name) -> list: 

74 values = node.locals.get(name, []) 

75 if not values: 

76 raise AttributeInferenceError(attribute=name, target=node) 

77 

78 return values