python - 如何在运行时在 Python 中从 stub 文件 (.pyi) 获取类型注释？

Question

我想获取函数或类方法的注释。如果类型提示写在源代码中，那么我可以通过获取属性__annotations__来获取类型。

def hoge(n: int): ...
print(hoge.__annotations__)  # {'n': <class 'int'>}

但我不知道如何将类型写入 stub 文件 (.pyi)。

# .pyi
def fuga(n: int): ...

# .py
def fuga(n): ...
print(fuga.__annotations__)  # {}

有什么很酷的方法吗？

Answer 1

来自 PEP-484 :

Stub files are files containing type hints that are only for use by the type checker, not at runtime. There are several use cases for stub files:

• Extension modules
• Third-party modules whose authors have not yet added type hints
• Standard library modules for which type hints have not yet been written
• Modules that must be compatible with Python 2 and 3
• Modules that use annotations for other purposes

很遗憾，无法获取注释，如何解释它们由类型检查器自行决定。这样做的副作用是没有权威资源可以验证您的类型提示是否正确。

最接近的是mypy .