put file back

Author: MarcoGorelli

README.md

@@ -1,4 +1,4 @@
-[![Build Status](https://github.com/pandas-dev/pandas-dev-flaker/workflows/tox/badge.svg)](https://github.com/pandas-dev/pandas-dev-flaker/actions?workflow=tox)
+![Build Status](https://github.com/pandas-dev/pandas-dev-flaker/workflows/tox/badge.svg)](https://github.com/pandas-dev/pandas-dev-flaker/actions?workflow=tox)
 [![Coverage](https://codecov.io/gh/pandas-dev/pandas-dev-flaker/branch/main/graph/badge.svg)](https://codecov.io/gh/pandas-dev/pandas-dev-flaker)
 
 pandas-dev-flaker

pandas_dev_flaker/_plugins_tree/single_letter_variables.py

@@ -0,0 +1,24 @@
+import ast
+from typing import Iterator, Tuple
+
+from pandas_dev_flaker._data_tree import State, register
+
+MSG = "PDF023 found assignment to single-letter variable"
+
+
+@register(ast.Assign)
+def visit_Assign(
+    state: State,
+    node: ast.Assign,
+    parent: ast.AST,
+) -> Iterator[Tuple[int, int, str]]:
+
+    # Unpacking is represented by putting a Tuple or List within targets
+    if isinstance(node.targets[0], (ast.Tuple, ast.List)):
+        assignment_names = node.targets[0].elts
+    else:
+        assignment_names = node.targets
+
+    for item in assignment_names:
+        if isinstance(item, ast.Name) and item.id != "_" and len(item.id) == 1:
+            yield item.lineno, item.col_offset, MSG