8th day of python challenges 111-117

venv/lib/python3.6/site-packages/astroid/brain/brain_attrs.py

@@ -0,0 +1,59 @@
+# Licensed under the LGPL: https://www.gnu.org/licenses/old-licenses/lgpl-2.1.en.html
+# For details: https://github.com/PyCQA/astroid/blob/master/COPYING.LESSER
+"""
+Astroid hook for the attrs library
+
+Without this hook pylint reports unsupported-assignment-operation
+for attrs classes
+"""
+
+import astroid
+from astroid import MANAGER
+
+
+ATTRIB_NAMES = frozenset(("attr.ib", "attrib", "attr.attrib"))
+ATTRS_NAMES = frozenset(("attr.s", "attrs", "attr.attrs", "attr.attributes"))
+
+
+def is_decorated_with_attrs(node, decorator_names=ATTRS_NAMES):
+    """Return True if a decorated node has
+    an attr decorator applied."""
+    if not node.decorators:
+        return False
+    for decorator_attribute in node.decorators.nodes:
+        if isinstance(decorator_attribute, astroid.Call):  # decorator with arguments
+            decorator_attribute = decorator_attribute.func
+        if decorator_attribute.as_string() in decorator_names:
+            return True
+    return False
+
+
+def attr_attributes_transform(node):
+    """Given that the ClassNode has an attr decorator,
+    rewrite class attributes as instance attributes
+    """
+    # Astroid can't infer this attribute properly
+    # Prevents https://github.com/PyCQA/pylint/issues/1884
+    node.locals["__attrs_attrs__"] = [astroid.Unknown(parent=node)]
+
+    for cdefbodynode in node.body:
+        if not isinstance(cdefbodynode, astroid.Assign):
+            continue
+        if isinstance(cdefbodynode.value, astroid.Call):
+            if cdefbodynode.value.func.as_string() not in ATTRIB_NAMES:
+                continue
+        else:
+            continue
+        for target in cdefbodynode.targets:
+
+            rhs_node = astroid.Unknown(
+                lineno=cdefbodynode.lineno,
+                col_offset=cdefbodynode.col_offset,
+                parent=cdefbodynode,
+            )
+            node.locals[target.name] = [rhs_node]
+
+
+MANAGER.register_transform(
+    astroid.ClassDef, attr_attributes_transform, is_decorated_with_attrs
+)