python - Pyright/mypy : "expr" has no attribute "id"

Question

代码:

def extract_assignment(assignment: ast.Assign) -> Dict[str, LINES_RANGE]:
    targets = ', '.join(t.id for t in assignment.targets)

pyright/mypy:

error: "expr" has no attribute "id"

来自typeshed :

class Assign(stmt):
    targets: typing.List[expr]
    value: expr

Answer 1

考虑以下代码:

x = [100]
x[0] = 200

运行以下 ast 检查:

import ast

code = """
x = [100]
x[0] = 200
"""

root = ast.parse(code)
for node in ast.walk(root):
    if isinstance(node, ast.Assign):
        print(type(node.targets[0]))

打印以下内容:

<class '_ast.Name'>
<class '_ast.Subscript'>

因此，在本例中，ast.expr 可以是 ast.Name 或 _ast.Subscript。只有 ast.Name 具有 id 属性。

要仅使用 ast.Name，请使用以下代码:

targets = ', '.join(t.id for t in assignment.targets if isinstance(t, ast.Name))