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二进文件类似对象的正确类型
原标题:Correct type for binary file-like object
I have the following functions defined using Python type-hinting: from typing import BinaryIO def do_something(filename: str): my_file = open(filename, "rb") read_data(my_file) def read_data(some_binary_readable_thing: BinaryIO): pass However my IDE (PyCharm 2017.2) gives me the following warning on the line I invoke read_file: Expected type BinaryIO , got FileIO[bytes] instead What is the correct type for me to use here? PEP484 defines the BinaryIO as "a simple subtype of IO[bytes]". Does FileIO not conform to IO?
最佳回答
This looks like a bug in either Pycharm or typing module. From the typing.py module: class BinaryIO(IO[bytes]): """Typed version of the return of open() in binary mode.""" ... Also the documentation specifies: These represent the types of I/O streams such as returned by open(). So it should work as stated. For now, a workaround would be to explicitly use FileIO. from io import FileIO def do_something(filename: str): my_file = open(filename, "rb") read_data(my_file) def read_data(some_binary_readable_thing: FileIO[bytes]): pass
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