.. py:currentmodule:: anyio
AnyIO provides asynchronous wrappers for blocking file operations. These wrappers run blocking operations in worker threads.
Example:
from anyio import open_file, run
async def main():
async with await open_file('/some/path/somewhere') as f:
contents = await f.read()
print(contents)
run(main)
The wrappers also support asynchronous iteration of the file line by line, just as the standard file objects support synchronous iteration:
from anyio import open_file, run
async def main():
async with await open_file('/some/path/somewhere') as f:
async for line in f:
print(line, end='')
run(main)
.. seealso:: :ref:`FileStreams`
AnyIO provides an asynchronous version of the :class:`pathlib.Path` class. It differs with the original in a number of ways:
- Operations that perform disk I/O (like :meth:`~pathlib.Path.read_bytes``) are run in a worker
thread and thus require an
await - Methods like :meth:`~pathlib.Path.glob` return an asynchronous iterator that yields asynchronous :class:`~.Path` objects
- Properties and methods that normally return :class:`pathlib.Path` objects return :class:`~.Path` objects instead
- Methods and properties from the Python 3.10 API are available on all versions
- Use as a context manager is not supported, as it is deprecated in pathlib
For example, to create a file with binary content:
from anyio import Path, run
async def main():
path = Path('/foo/bar')
await path.write_bytes(b'hello, world')
run(main)
Asynchronously iterating a directory contents can be done as follows:
from anyio import Path, run
async def main():
# Print the contents of every file (assumed to be text) in the directory /foo/bar
dir_path = Path('/foo/bar')
async for path in dir_path.iterdir():
if await path.is_file():
print(await path.read_text())
print('---------------------')
run(main)