Merge pull request #3472 from Textualize/fix-bad-dataclass

fix for missing field in dataclass

Author: willmcgugan

CHANGELOG.md

@@ -23,6 +23,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Fixed superfluous space above Markdown tables https://github.com/Textualize/rich/pull/3469
 - Fixed issue with record and capture interaction https://github.com/Textualize/rich/pull/3470
 - Fixed control codes breaking in `append_tokens` https://github.com/Textualize/rich/pull/3471
+- Fixed exception pretty printing a dataclass with missing fields https://github.com/Textualize/rich/pull/3472
 
 ### Changed
 

rich/pretty.py

@@ -781,7 +781,9 @@ def iter_attrs() -> (
                 )
 
                 for last, field in loop_last(
-                    field for field in fields(obj) if field.repr
+                    field
+                    for field in fields(obj)
+                    if field.repr and hasattr(obj, field.name)
                 ):
                     child_node = _traverse(getattr(obj, field.name), depth=depth + 1)
                     child_node.key_repr = field.name

tests/test_pretty.py

@@ -734,3 +734,23 @@ def __rich_repr__(self):
             yield None, (1,), (1,)
 
     assert pretty_repr(Foo()) == "Foo()"
+
+
+def test_dataclass_no_attribute() -> None:
+    """Regression test for https://github.com/Textualize/rich/issues/3417"""
+    from dataclasses import dataclass, field
+
+    @dataclass(eq=False)
+    class BadDataclass:
+        item: int = field(init=False)
+
+    # item is not provided
+    bad_data_class = BadDataclass()
+
+    console = Console()
+    with console.capture() as capture:
+        console.print(bad_data_class)
+
+    expected = "BadDataclass()\n"
+    result = capture.get()
+    assert result == expected