Python:使用异步/等待的递归
这是一些用于遍历文件树的简单工作代码。它采用了同步发电机的概念:Python:使用异步/等待的递归,python,recursion,async-await,Python,Recursion,Async Await,这是一些用于遍历文件树的简单工作代码。它采用了同步发电机的概念: def list_dir_groom(abs_path): """Returns the list of directories and the list of files ([abs_path] offspring). """ dirs, files = [], [] for i in os.listdir(abs_path): if i[0] != ".":
def list_dir_groom(abs_path):
"""Returns the list of directories
and the list of files ([abs_path] offspring).
"""
dirs, files = [], []
for i in os.listdir(abs_path):
if i[0] != ".":
x = abs_path.joinpath(i)
if x.is_dir():
dirs.append(x)
else:
if is_target_file(x):
files.append(x)
return dirs, files
def traverse_target_tree(tgt_dir):
"""Recursively traverses the target directory [tgt_dir]
and yields a sequence of file names.
"""
dirs, files = list_dir_groom(tgt_dir)
for d in dirs:
yield from traverse_target_tree(d)
for f in files:
yield f
def tweak():
"""Tweak all files.
"""
for i in traverse_target_tree(ARGS.tgt_dir):
print(f"{i}")
出于教育目的,我一直在尝试使用asyncio
(python3.8.1)重写它。这当然不能正常工作:
async def traverse_target_tree_async(tgt_dir):
"""Recursively traverses the target directory [tgt_dir]
and yields a sequence of file names.
"""
dirs, files = list_dir_groom(tgt_dir)
for d in dirs:
yield traverse_target_tree_async(d)
for f in files:
yield f
async def tweak_async():
"""Tweak all files.
"""
async for i in traverse_target_tree_async(ARGS.tgt_dir):
print(f"{i}")
...
asyncio.run(tweak_async())
示例输出如下所示:
<async_generator object traverse_target_tree_async at 0x7f4993429ca0>
<async_generator object traverse_target_tree_async at 0x7f4993429d30>
<async_generator object traverse_target_tree_async at 0x7f4993429ca0>
<async_generator object traverse_target_tree_async at 0x7f4993429d30>
/home/user/spaces/python/tex-tweak/n.vim
/home/user/spaces/python/tex-tweak/README.md
/home/user/spaces/python/tex-tweak/pyproject.toml
/home/user/spaces/python/tex-tweak/poetry.lock
/home/user/spaces/python/tex-tweak/n.vim
/home/user/spaces/python/tex-tweak/README.md
/home/user/spaces/python/tex-tweak/pyproject.toml
/home/user/spaces/python/tex-tweak/poetry.lock
在某种程度上,这是有道理的,但我不知道我应该做的最后一步是什么。建议了解决方案。多亏了
测试脚本会很困难,因为它不是一个最小的可执行示例。但是无论如何,如果您将异步上下文中的
yield-traverse\u-target\u-tree\u-async(d)
更改为yield-from-traverse\u-target\u-tree\u-async(d)
yield-from
是一个语法错误,这是正确的。啊,我甚至不知道。。。使用async for
手动扩展它怎么样?这个答案应该是有帮助的:旁注:os.listdir
比os.scandir
差得多,特别是当你想测试它是否是一个目录时(由scandir
返回的DirEntry
可以免费告诉你,而你目前的方法要求每个文件都有一个stat
)。
async def traverse_target_tree_async(tgt_dir):
"""Recursively traverses the target directory [tgt_dir]
and yields a sequence of file names.
"""
dirs, files = list_dir_groom(tgt_dir)
for d in dirs:
async for f in traverse_target_tree_async(d):
yield f
for f in files:
yield f